Simple iPhone video taping an accident revises initial thoughts on cause

I was retained to investigate the cause of an accident involving the plaintiff using one of his tools.  People have been killed using this type of tool, it’s that dangerous.  The plaintiff believed there was a defect in the tool.  Graphic photographs of his injuries would certainly lead you to believe that - an initial hypothesis.

I was asked to peer review a report by another engineer and to examine the tool for wear sufficient to cause the accident.

The other engineer reported test-using the tool but, as evident in his report, not during a re-enactment of the accident.  He found a few things wrong with the tool but nothing to suggest it was defective.

I was surprised that the engineer did not re-enact the accident considering his stated years of experience investigating accidents.

I reviewed the report, researched howhis  the tool operated and examined the exterior.

I video taped the plaintiff re-enacting the accident and recorded his explanation of how he was injured.  I had him do this three times just to be sure and video taped his demonstration from different angles.

Evidence from the video and the interview was quite revealing as to cause but questions arose when this evidence was considered in light of evidence from the graphic pictures of the plaintiff’s injuries.

I retained a tool repairman to dismantle the tool and visually examine the interior surfaces for wear and defects.  He found nothing.

At this point in my investigation:

  • The nature of the injuries depicted in the pictures suggested one cause
  • The re-enactment suggested a different cause
  • The tool operated properly according to the repairman, supporting the different cause

The tie-breaker – justifying modifying the initial hypothesis on cause - were comments by the plaintiff during his interview on how he was using the tool coupled with how the tool operated.  Turns out he was using the tool in the most dangerous way, but one of several ways it could be used.  Also turns out that the material he said he was using didn’t exist as he described, except as a special order.  A similar, readily available material suited to the job he was doing could explain the contradiction raised by the graphic pictures.

To summarize the tie-breaking bullets:

  • The plaintiff said that he was using the tool in the most dangerous way, supporting the different cause noted above
  • The material he probably was using could explain a contradiction in the graphic injury pictures, also supporting the different cause

Based on the evidence, I modified my initial hypothesis that a defect caused the accident to believing that the plaintiff caused the accident by his actions when using the tool in the most dangerous way.


A spoiler?  As noted above, the plaintiff reported using the tool in the most dangerous way.  But, on being retained, I was given the tool rigged to be used in one of the safest ways.  This might have spoiled my modified hypothesis, but didn’t - the tool had passed through at least four sets of hands by the time I got it.

My client decided against further forensic investigation.


Design, manufacture/construction and maintenance/repair are three main stages in development and use of an item in the built environment, like a tool.  My investigation covered maintenance/repair when assessing if the tool in this incident was defective.

Retaining experts in design and manufacture to examine the tool would be a stage in a forensic investigation like this.  However, taking this step would not be justified considering the strength of the modified hypothesis and the cost of experts in design and manufacture.

My investigation several years after the incident cost money.  It would have cost less, as would the civil litigation in general, if I could have interviewed the plaintiff several days after the incident, or after my client took the case, and video taped him re-enacting the accident.  I’m certain the evidence from such simple tasks would have cast the merit of the case and the worth of the file in a quite different light.

Case take-aways

My take-away from this case is to get my iPhone out of my back pocket and video tape a re-enactment of an accident ASAP and have the victim describe it.  It might be rough – iPhone forensic video - but this quick and dirty stuff can pay dividends in a forensic engineering investigation.

My client’s take-away? Possibly an old saw – retain an expert early preferably during the merit assessment stage or a few days afterwards and save money on civil litigation.





Sinkholes: A litigious matter?

Sinkholes, like the one that undermined the house in Falmouth, Nova Scotia last week, are a serious issue for subdivision and lot developers.  As reported in the newspapers, the risk of sinkholes forming in an area can be known from published maps. (Refs 1, 2)  And the cavities in the ground associated with sinkholes can be found – before construction.

Sinkholes start their life as roofed-over cavities at some depth in the limestone, gypsum and salt deposits beneath an area.  The cavities get bigger and the roof gets thinner as rock like this dissolves in the ground water.  In a sense, the cavities “migrate” to the ground surface and eventually break through as sinkholes.  The fairly precise size, location and depth of cavities can be determined beforehand.

The technology for locating cavities in rock is well developed and has been around a long time.  It’s called ground penetrating radar, GPR for short, and it’s well known to experienced geotechnical engineers.  I used GPR years ago to locate cavities beneath an airport runway on South Andros Island in the Bahamas.  The same technique is used for locating unmarked graves.

It sounds technical but all it involves is sending radio waves into the ground and analysing what is reflected back.  There’s nothing too exciting in the data that comes from uniform soil or intact rock.  But lots of excitement in the data from a cavity, a well-recognized anomaly to the GPR operator – and a potential sinkhole beneath a building. The remote sensing, non-intrusive technique is not unlike CAT scans and MRIs in medicine.

The type of potential sinkhole I was looking for at the airport is called a banana hole. So named because banana plants grow in the sinkholes once the cavities break through the surface.  A banana hole/sinkhole can be seen in the runway by an inbound pilot but not the roofed-over cavity just before it breaks through the surface.

Geo engineers investigate the adequacy of the foundation soil and rock conditions beneath a site where someone wants to build something – like a house, for example, or a bridge, dam, or airport runway.  The conditions would not be adequate if there was a cavity beneath the building site.

GPR would not normally be used on a building site in the Atlantic provinces, nor in Canada for that matter.  But it certainly should if deposits of limestone, gypsum and salt are noted when the engineer checks the published geology of the site – an important and standard task in a geo investigation.  These types of rock with their inherent risk are not so common but they do exist as noted in the news report on the Falmouth sinkhole.

If there’s a risk and the technology is available to quantify it, and it’s not used, then it seems to me it’s a potentially litigious matter.


  1. Falmouth: Sinkhole wrecks family’s house, pg. 1, The Chronicle Herald, Halifax, Tuesday, September 5, 2017
  2. Geological conditions: Sinkholes not unusual in N.S.: Scientists, pg. 1, The Chronicle Herald, Halifax, Wednesday, September 6, 2017

A Bundle of Blogs: How to manage the cost of civil litigation involving experts

The following blogs – and good reference material in some - will help you manage the cost of civil litigation involving experts.  Careful management is necessary because most cases are small or medium sized not big - ”less affluent, not affluent” to reflect comment by The Advocates Society, Ontario. (Ref. 1)  Yet lawyers must still prepare before going to trial (Ref. 2) and experts must investigate before giving an opinion - regardless the size of the case.  Proper preparation and investigation can be expensive.

These blogs describe things you can do to keep tabs on costs.  Some ideas echo the principles followed in the well-developed field of project management.  Several suggestions, like the following, stood out as I reviewed my postings of the past five years:

  • Retain an expert early
  • Retain one according to your needs – by one count, 10 different ways
  • Confer with s/he often
  • Work together to identify the key technical issues that must be investigated

There are a number of helpful suggestions in the following list in addition to the bulleted ones above.  The chronological list also gives some idea of how my insight has developed over the years.

The list of blogs gives the title in bold and the date I posted it so it’ll be easy to locate on this site, the one you’re on -   I’ve reviewed each recently and added a comment on some of the ways each posting can help you - read my comments if nothing else:  There’s something for everyone in the following list.

  1. “Technical” visual site assessments: Valuable, low cost, forensic method.  Posted September 4, 2012 … A good read on the cost effectiveness of a simple visual assessment by an expert of the scene of a failure or accident.  Have this done before detailed investigation is begun - ideally when you assess the merit of the case and the worth of the file.  It’ll save money.  The blog includes examples from my practice, some of which show the value of this inexpensive method before an advocate actually decides to take a case.  I know of one case that such an assessment would have saved the luckless client many 1,000s of dollars (I was retained late in the case to peer review the forensic investigation).
  2. Steps in the forensic engineering investigative process with an Appendix on costs.  Posted July 15, 2013 … A detailed outline of the tasks in forensic work with brief comment on the difficulty estimating cost taken from a previous blog.  A must-read for non-technical people who must confer with experts.
  3. Difficulty estimating the cost of forensic engineering investigation.  Posted July 23, 2013 … Another must-read.  Examples taken from my files illustrate the difficulty.
  4. (Fairly easy) Estimating the investigative cost of a catastrophic engineering failure.  Posted August 13, 2013 … The pictures of this failure are amazing!  Also my concluding remark considering the magnitude of the failure shown in the pictures: “So, estimating the cost of investigating the cause of a catastrophic failure is not always difficult.  And, if you don’t mind, estimating the cost of investigating a simple failure is not always easy.” 
  5. Managing the cost of civil litigation.  Posted September 19, 2013 … Outlines a detailed, stepped process for managing costs.  Based on principles from the well-developed field of project management.  The process is characterized by frequent updates on cost-to-date and estimated cost-to-complete, for both legal and expert involvement in a case.
  6. How to manage the cost of civil litigation.  Posted October 4, 2013 … A good read with lots of ideas.  An update of a previous blog that expanded the section, “Why must cost be managed?”  Contains a list of helpful references.
  7. Reducing the cost of forensic investigation – it’s being done now by default not by plan.  Posted September 14, 2014.  You may see your actions reflected in this blog.  An insightful read.
  8. Why the difficulty estimating the cost of forensic engineering investigation?  Posted September 1, 2013 … A must read.  A good, detailed review of what engineering experts are up against when attempting to estimate the cost of the different tasks in a forensic engineering investigation.
  9. “If you measure it you can manage it” – and do thorough forensic engineering and cost effective civil litigation.  Posted June 18, 2015 … A real good, short read and helpful in cost management.
  10. “Expensive” experts are not so expensive compared to the cost of key technical issues going undetected.  Posted December 8, 2015 … Contains good advice from noted and respected authorities in the legal profession.  Also lessons learned from a few cases I’m familiar with.
  11. Peer review costs can be controlled.  Posted January 22, 2016 … A good read on managing the cost of civil litigation costs by how you retain an expert.  See at least 10 ways if you count retaining an expert at the case merit-assessment stage or as a testifying expert.
  12. Cost control in civil litigation.  Posted September 8, 2016 … Some blunt comment on managing costs in a suggestion to APTLA (the Atlantic Provinces Trial Lawyers’ Association) to hold a conference or include a session on managing the costs of civil litigation involving experts)
  13. Keynote speaker on cost control in civil litigation.  Posted September 22, 2016 … A follow up suggestion to APTLA on how to organize a conference on cost management of civil litigation involving experts that would include keynote speakers from both the legal and expert communities.
  14. Managing the cost of civil litigation when experts are involved.  Posted March 19, 2017 … Explains a low cost method of doing this - basically, counsel and expert meeting very early in the case and talking about the technical issues.  If possible, investigating one or two technical issues certainly results in less expensive civil litigation than investigating several.  Examples from my files of cases that went well, and one case – not so much.
  15. Conference call on a “drone flight” reduces the cost of civil litigation.  Posted May 18, 2017. (Also see a blog posted March 31, 2017) … I’m getting a lot of cost effective evidence with unusual investigative techniques.  For example, with aerial video and photography from a low flying drone.  Also learning the source of water at a slip and fall accident site by taking a cold shower at the site.  And measuring the skid resistance of a floor with a piece of pig’s belly.  Advocates and experts must be receptive to non-textbook tricks in the interest of managing the cost of civil litigation.
  16. “A rose by any other name…”; Primers for lawyers.  Posted December 19. 2016 … An insightful blog inspired by a lawyer’s comment at an APTLA conference last November. (Ref. 2)  He was right on the money.  A lawyer must prepare before going into court and an expert must investigate before giving an opinion – and this can be expensive.  A good blog on a client’s need to know.
  17. An expert’s fees and forensic engineering.  Posted July 5, 2016 … An indication of the average hourly billing rates for professional engineers in the Atlantic provinces for different levels of experience and responsibility.  Rates not too much different than lawyer’s fees.  Knowing these helps in managing the cost of civil litigation.


  1. The Advocates Society, Toronto, Ontario, Principles governing advocates communicating with testifying experts, June, 2014.  Posted June 11, 2015
  2. Pizzo, Ron, Pink Larkin, and his comment “…lot of preparation beforehand – a lawyer just doesn’t walk into court”.  APTLA conference, It’s all wrongful: Death, Dismissal, Conviction & More, Halifax, November 4, 2016



Drone video as a forensic technique is joined by drone photography as an art form

I enjoyed learning recently about the annual international drone photography contest.  The contest was mentioned in the papers and, of course, I learned more by Googling.  I liked what I read and saw.

The contest recognizes that drone photography is more than fun indulged in by hobbyists with $300 drones and more than a surveillance technique used by the RCMP with $30,000 gear.  It’s an art form, and on the list with its use as a valuable forensic engineering technique using a $10,000 drone fitted with a camera.

The winning and runner-up photographs in the contest are impressive - you must go online and see if there is an artistic bent to your nature at all.  Impressed is the way I felt too when I first saw drone video of one of my forensic sites.

The contest photographs are submitted in four categories: Nature, People, Urban and Creativity by drone photographers from everywhere in the world.  Profiles of the professional and amateur photographers are included on the contest site.

The photographs are judged by a panel of experts that include representatives from National Geographic in France and the US, and from Kodak.  Both companies are two of several high profile sponsors of the annual competition.  This year, 2017, is the fourth year the contest has been held.

Such quality in photography and high profile in contest sponsorship is telling about the future of this photographic technique.  It echoes the increasing success I’m having in my forensic investigations getting evidence with a drone and presenting it to my earthbound clients.


  1. Some of the content in this blog has been taken from the drone contest website and also a conversation with Robert G. Guertin, Millenium Film & Video Productions, Dartmouth, NS, Canada.


“Unexpected” evidence and the importance of drone photography in forensic investigation

I was impressed a few months ago by the unexpected evidence I got from video of a site taken from a drone.  Impressed to the extent that I flew another site a few days ago, but this time looking for the “unexpected” evidence.  The experience confirmed the importance of filming the site of a forensic investigation from a low flying drone.

A few months ago I videotaped a compact site – couple of 100 feet square – for record purposes.  I did this for 35 minutes from several 10s of feet. On looking at the video I saw a feature of interest relevant to the problem I was investigating.  It was not evident when I walked across the site in an earlier visit.

Talking with the property owner later I learned that the feature seen in the video marked a characteristic of the ground that was very important to understanding the problem I was investigating.

A few days ago, I video taped a long, narrow site – 1,500 ft. x 200 ft. – from an altitude of several 100s of feet as well as 10s of feet.  This time, however, I looked for a feature in the video that I had seen on the ground at one end of the long site.  It was relevant to the problem I was investigating.  I found it, then studied the video for the occurrence of the feature elsewhere along the length of the site and noted these locations. This was sort of the reverse of the situation at the compact site.

Put another way, a few months ago I identified a feature of interest in a video, and had it confirmed on the ground.  A few days ago I identified a feature of interest on the ground and had its location elsewhere on the site confirmed with a video.


This process is called terrain analysis in engineering:

  • You identify the different features at the ground surface appearing in aerial photographs,
  • note the characteristics of the subsurface implied by the shape and look of each of the different features,
  • then assess how these subsurface characteristics relate to one another and to the problem you’re investigating.

For example, how does the strength of the subsurface soils relate to the foundation failure of a building, bridge or highway?  Or the subsurface drainage characteristics relate to the location of fuel oil spilled on the ground some time in the past?

I’ve done terrain analysis for years using aerial photography often taken from 6,000 feet – a long way up.  It has been useful – but not at all, at all like the detail you get from low level drone photography.


The drone videotaping at the compact and long sites was similar.  Take orientation video from the four sides of the site from a high altitude then close up video of different features at a low altitude.

I’ll study the video of the long site in greater detail then select optimum places on the ground – representative and cost effective – for collecting subsurface data and solving the problem I’m investigating.  The data won’t really be “unexpected”.  I’ll get what I expect to get – the depth to the water table, and water and soil samples for testing.

The unexpected evidence a few months ago reminded me about the value of aerial photography in forensic engineering investigation, and the greater value today of low level, drone photography.  I was also reminded to be on guard against the tyranny of the obvious, to expect the unexpected in forensic work.


Why do I blog?

I blogged for different reasons the past five years (see Ref. 1 for a good read) including simply liking to write, expressing myself that way.  I also belong to a group that could be characterized as a story-writing and -telling group.  Chronicling a forensic investigation is telling the story of the investigation – a good and simple way of explaining it to the judicial system.

But I’ve realized even more lately that striving to blog well, write well, partly out of respect for my readers, trains me in another way:  To think and analyse on paper, formulate an opinion then present it in a well-written expert’s report.  And it’s so effective when you get to the word processor stage after the cursive writing stage.

I’m in the middle of analysing data now on two cases and formulating opinions.  It will go on for a good few days yet as I turn the data over in my head and squeeze the truth of each matter out on paper - also as more data comes in from follow-up investigations.

There’s a lot implied in the words forensic engineering and a lot of writing is involved at some stages:

  • Investigate the cause of a failure or accident
  • Examine and observe
  • Measure and test
  • Analyse and assess
  • Draw conclusions
  • Formulate opinions
  • Present reliable evidence to counsel and the court or tribunal in simple, non-technical English in well-written, experts’ reports

Reaping the benefits of writing/blogging is not unique to me nor is it new.  Journalizing in some form as a means of working things out – e.g., your thoughts – drafting a talk or preliminary report, noting an item to remember - has been around a long time.  I carry a journal with me most times to capture a thought along the way (I don’t like to dictate to my cell phone because of security issues)

It’s just that it’s not so very technical-sounding – thinking on paper - even though it has an important role in the different stages of forensic investigation.  I like to think, “I knew that!”, the benefits, but the penny did drop and make a louder noise recently.  I thought I must tell you this.


  1. Why do I blog on forensic engineering investigation? Posted July 22, 2016.



Using “Skippy”, a full sized dummy, to get the speed of a car in a fatal traffic accident

How fast was he driving when he hit the girl on the sidewalk?  He’s dead now after falling asleep at the wheel, hitting the girl then hitting a pole.  So’s the girl after sliding several metres in the grass.  Speed is important in reconstructing an accident like this.

His speed can be assessed from the damage to his car.  It’s called a “crush” analysis, not surprisingly.  The assessment can be cross-checked with a different analysis using data from the skid marks of the girl in the grass.

Experts in accident investigation like to cross-check assessments like these – and also refine the analytical methods with new data.  Some of the methods are rough and seemingly not very scientific but that’s hands-on engineering and better than nothing.  If you can measure something – e.g., skid marks, crush shape - even approximately, you can “manage” it; in this case get the speed of the car.

That’s what I was doing last week at a meeting in Moncton of CATAIR, taking part with about eight others collecting data for the continued refinement of an analytical technique.  This time using the skid marks of a body in the grass for determining the speed of a vehicle during an accident.  It sounds complicated but a lot of it boils down to determining the coefficient of friction of a surface like in simple high school physics.

With enough testing, chaps like Mike Reade, Moncton hope results will benefit investigators in situations when they only know the pedestrian’s sliding/tumbling distance after an accident.  The results will be shared with others who work in this field. (Refs 1, 2)

In this case, Mike, who was directing the research and will crunch the data later, threw Skippy, a full size dummy, from a speeding pickup truck driven by Ken Zwicker, Bridgewater.  The rest of us carried out various tasks like spotting where Skippy hit the ground, measuring how far he slid and videotaping what happened to him after he was “hit” by the truck.  Katelynn Everett, a consulting professional engineer from Fredericton, recorded data and did preliminary number crunching.

The field trials are part of the very impressive, ongoing work by CATAIR, the Canadian Association of Technical Accident Investigators and Reconstructionists, and others to refine the analytical methods used by traffic accident investigators. (Refs 2 to 7)

The association is a mix of serving and former RCMP and municipal police officers, professional engineers and technologists all of whom are interested in traffic accident investigation and reconstruction.

In the morning before starting the field trials we met and discussed about 12 different courses on topics related to traffic accident investigation that are available to CATAIR members.

CATAIR meets somewhere in the Atlantic provinces about three or four times a year and do field tests most times.  Recently three teams measured the crushed shape of three different cars that had been involved in traffic accidents.  Each team is analysing speed using different methods and comparing results – Stu Smith, Dartmouth gave a brief report at the meeting on his work on this.  Another time the stopping distance of a vehicle on a road was measured.  And another time still, the turning radius and the path of the rear wheels of a school bus were measured.

Nobody gets paid for this field research.  It’s all to do with refining our understanding of the cause of traffic accidents and reconstructing these, and the camaraderie of like-minded people working together – we do have fun when we’re getting our hands dirty and mud on our boots.


  1. Reade, M. W. (Mike), Personal communication. June, 2017
  2. Reade, M. W. (Mike) and Becker, T. L. (Tony), Fundamentals of Pedestrian/Cyclist Traffic Crash Reconstruction, Institute of Police Technology and Management (IPTM), Jacksonville, FL 2016
  3. Civil litigation, forensic engineering and motor vehicle accident reconstruction.  Published September 22, 2015
  4. Is your traffic accident investigator well trained, experienced and “accredited”?  Published February 23, 2016
  5. “Seeing is believing” at a meeting of traffic accident investigators.  Published March 4, 2016
  6. If you  can measure it you can manage it, even if it’s a real mess like a car or truck accident.  Published June 23,, 2016
  7. Forensic assessment of traffic accidents.  Published October 26, 2016


What guides the ‘rhyme or reason’ of forensic engineering investigation?

What guides civil engineers carrying out a forensic investigation?  What ensures we do thorough work and give an objective opinion – in keeping with the requirements of the judicial system?  There’s usually little on this in the Appendix of an expert’s report so you could be excused for wondering.

There are, in fact, excellent guidelines in place and some are well thought out after decades of development.  They ensure the judicial system is well served.  And they’re enhanced by rules-of-thumb like the following picked up by experienced engineers over the years.

  1. Follow the evidence – an old chestnut that – for certain evidence that leads to follow-up investigations
  2. If you need more data, get it
  3. If in doubt, go deeper, particularly if the foundation soils are involved in a failure
  4. Expect the unexpected
  5. Beware the tyranny of the obvious when determining the cause of a failure
  6. Get your hands dirty and mud on your boots – get out on the site of a failure; no excuses
  7. If you can measure it you can manage it, particularly if the failure involves the natural environment as well as the built environment

I thought to mention the existence of guidelines to advocates and adjusters for a while now, particularly when a client is retaining an expert for the first time.  Also when the failure is small or medium sized as most are – not catastrophic and newsworthy – and the budget is small.  The standards are high regardless the size.

I looked through my library and found about three and a half dozen books that have guided me carrying out forensic investigations over the years.  Your eyes might glaze over at such a list.  But take a look at the following selection and be assured that civil engineers are being well guided, particularly by the literature from ASCE and SEAK.

The American Society of Civil Engineers (ASCE) has been guiding civil engineers in practice since about 1857 – 160 years – longer than Canada’s 150 years!  SEAK has been reviewing 1000s of case histories involving experts for more than 30 years, learning from what they read and passing it on to experts.  There’s a lot of guidance out there and a high standard set for civil engineers.  You can see it in the titles of the following::

  1. Lewis, Gary L., Editor, Guidelines For Forensic Engineering Practice, 2nd edition, American Society of Civil Engineers, ASCE, Reston, Virginia 2012
  2. Greenspan, Howard F. et al, Guidelines for Failure investigation, ASCE, Virginia, 1989
  3. Janney, Jack R., Guide to Investigation of Structural Failures, 2nd edition, ASCE, Virginia, 1986
  4. Ratay, Robert T., Forensic Structural Engineering Handbook, McGraw-Hill, New York 2000
  5. Nicastro, David H., Editor, Failure Mechanisms in Building Construction, ASCE, Virginia, 1997
  6. Noon, Randall K., Forensic Engineering Investigation, CRC Press, Inc., Boca Raton, Florida 2000
  7. Mangraviti, Jr., James J., Babitsky, Steven and Donovan, Nadine Nasser, How to Write an Expert Witness Report, 2nd edition, SEAK, Inc., Falmouth, Mass. 2014
  8. Zinnsser, William K., On Writing Well: The Classic Guide to Writing Nonfiction, 7th edition, Harper Collins, New York 2006
  9. Roberts, Donald V., Expert: A Guide to Forensic Engineering and Service as an Expert Witness, Association of Soil and Foundation Engineers, ASFE, 1985
  10. Speight, James G., The Scientist or Engineer as an Expert Witness, CRC Press, Boca Raton, Florida 2009
  11. Cohen, Kenneth S., Expert Witnessing and Scientific Testimony, CRC Press, Boca Raton, Florida 2008
  12. Babitsky, Steven and Mangraviti, Jr., James J., The Biggest Mistakes Expert Witnesses Make and How to Avoid Them, SEAK, Inc., Falmouth, Mass., 2008
  13. Stockwood, Q.C., David, Civil Litigation, 5th edition, Thomson Carswell, Toronto 2004

I don’t expect you to check out these references too thoroughly, certainly not read them. Just know that civil engineers are guided by good literature on how to carry out thorough forensic engineering investigations and render objective opinions.  And experienced engineers have their rules-of-thumb.

A thought: What guides your expert carrying out a forensic investigation in their field of study if s/he is not a civil engineer?


Conference call on a “drone flight” reduces cost of civil litigation

I had a conference call with a property owner while both of us were viewing aerial video of the property taken from a low flying drone.  It was a cost effective way of resolving some technical issues about the property without a day long trip plus time on site.

I took the video earlier during my forensic investigation of a problem there.  While analysing the video I concluded I had found key evidence relevant to the problem.  But like all air photo interpretation, ground-proofing was in order – get boots on the ground and your hands dirty confirming what you thought you saw.  This is a basic technique in civil engineering and terrain analysis.

I mailed a CD of the video to the property owner, then called and asked the owner to load the video on a computer, go to a certain frame on the video – easy to do with a counter at the bottom of the video – and tell me why the site looked the way it did at that location.  The owner did that and confirmed my interpretation of the surface conditions there - plus added to the significance of the evidence with some history of that part of the site.

It truly was a windfall of data got during a conference call with my client while each of us viewed the video.  Who would have guessed made possible with a drone - a device that may have started life as a simple toy flown by kids in backyards? (Ref. 1)

I’ve since thought about splitting computer screens and Skyping on one screen with my client while viewing aerial video on the other.  Just now I’m realizing I can examine anything on a split screen with a client while Skyping with him/her on another.


We then “toured” the rest of the property via the aerial video and confirmed the location of other features relevant to the problem.  I had seen these features on site but wanted to hear the client talk about them.  Surprisingly, another feature of the site was noted that was not so evident on the ground nor in the video.  It also was evidence relevant to my client’s problem.

So, all in all, quite a conference call.  There’s no question this method has gone into my arsenal of forensic engineering investigative methods.  A method that will also reduce the cost of civil litigation.


  1. Bartlett, P.Eng., Gary. Wellington, Nova Scotia. Private communication

Peer review pays off – 17 years later

Monitoring the clean-up of a fuel oil spill in 2000 paid off early this year.  The pay-back was the recent opening of a file at the Nova Scotia DOE based on records I kept that confirmed the residential property had been cleaned up.  I was retained at the time to ensure the remediation conformed to good engineering practice – peer review.

(By contrast, the benefit from peer review in civil litigation - quality control of the thoroughness and objectivity of the forensic investigation - is immediate, rather than years later. Refs 1, 2 and 3)

A DOE file on a residential property is normally opened after fuel oil spills and closed on receipt of a report that the property has been cleaned up.  It was missing in DOE’s files as the property owner – my client 17 years ago – learned in anticipation of selling his property.  Buyers and sellers both want assurance that a property is clean and that comes from DOE’s files.

My client asked and I confirmed that I had a copy in my files of the final report by the engineering firm who did the remediation plus all my field notes and photographs taken during my work.

Why the usual file was missing 17 years later is not so important to my story – except to draw attention to the worth of peer review.

The story began in early 1999 when my client smelled oil in his home.  Investigation by a consulting engineering firm at his neighbour’s property uphill found that a 200 gallon furnace oil tank had leaked an unknown quantity of fuel oil.

The firm supervised the remediation of the property.  This involved locating and excavating the contaminated soil and removing it from the property.  Some soil was also excavated from my client’s property.

My client, a retired professional engineer, wasn’t so happy with the firm’s recommendations for remediating his property.  At his request, the insurance company retained another consulting engineering firm to do an independent assessment – in a sense, the start of the peer review process.  This was done and their assessment was accepted.  The second firm then went on to direct remediation of my client’s property.

My client was still uneasy because of the two sets of consulting firms and clean up operations on adjoining residential properties.  He retained me to monitor everything that took place on his property.

Remediation of fuel oil spills is fairly simple in most cases in the Atlantic provinces relying as it does on the scientific method and basic engineering.  It just looks difficult because it’s messy.  Remediation involves:

  • Learning the location of the oil or where it might have drained,
  • Sampling and testing the soil and ground water for oil at those locations,
  • Removing soil that has too much oil by acceptable standards, and,
  • Replacing the contaminated soil with clean soil.

Possible locations are identified by:

  • Characterizing the drainage pathways of the subsurface soil - the medium that the oil will flow across and through – often, simply contouring the surface of the ground, and,
  • Also determining how foundations are constructed on a site that might be affected by soil that has too much oil.

An analogy: Spill water on your house floor, and in mopping it up you look where some of it has drained because you know the floor is almost level, but not quite - the character of floors.  And you clean it up because the floor might be damaged by the water if it’s not.


Peer review is checking that something has been done to an acceptable standard.  We often associate it with review of a report – check that it’s well written and that the data has been analysed according to scientific principles.  It can involve confirming that the forensic investigation was carried out to an acceptable standard and the data is reliable.  Peer review can also mean checking that something is being done properly as it’s being done – the situation at my client’s properly.

“Hot tubbing” might be thought of as a form of mutual peer review – experts from different parties in a civil litigation case gather round in a meeting and review each other’s report.  It’s increasingly accepted as a case-expediting and cost management technique. (Ref. 4)

In my case in 2000 I was on site full time to note what was done and that it conformed to good practice, to independently measure and photograph the clean-up as it progressed, attend site meetings and report daily to my client.

In general, the work was done very well, and good records kept that saved the day 17 years later.  There was one issue about the need to construct a groundwater monitoring well - a way of checking for oil in groundwater over time, oil that we don’t want.  This resulted in independent investigations, reports and opinions – including my own.  There’s always a few issues that are resolved by experienced engineers talking.


Peer review cost my client money.  But it would have cost him an awful lot more money if he tried to sell his house and the word on the street was of an oil spill on the property and no records were available that it was cleaned up properly.

It’s not too much different in civil litigation.  A cost up front for peer review of a forensic investigation, or a much greater cost later when rebuttal of an inadequate investigation and a poorly written expert’s report is turned into a nightmare. (Refs 3 and 5)


  1. Peer review in forensic engineering and civil litigation.  Posted November 26, 2013
  2. Peer reviewing an expert’s  report ensures the justice system gets what it needs.  Posted January 15, 2016
  3. Peer review costs can be controlled.  Posted January 22, 2016
  4. Biased experts cured with a soak in the “hot tub”.  Posted January 31, 2017.
  5. Mangraviti, Jr., Babitsky, Steven and Donovan, Nadine Nasser, How to Write an Expert Witness Report, the Preface, SEAK, Inc, 2014