Some forensic investigations end suddenly and unexpectedly, reveal the simple cause of the problem and leave the expert feeling soooo good. Others age us with their head-scratching complexity.
I thought this – and to tell you about it – on reading some stories in one of the chicken-soup-for-the-soul books, The Magic of Moms. They are warm, feel-good stories that end nicely just like some forensic investigations. They’re also well written, reason enough to read and learn from them for writing expert reports.
Some examples of chicken-soup-for-the soul forensic investigations
Example #1 One of my investigations involved re-enacting a fatal motor vehicle accident. The accident happened when the car struck an obstacle in the road at a speed of 50 mph. I decided to re-enact striking a similar obstacle but initially at a lower speed.
I had safety procedures in place but the car behaved so erratically at 20 mph that I knew I needed even more safety procedures. Like a rescue crew that could get me out of an overturned car.
Then the penny dropped and I realized that if the obstacle could potentially cause an accident at 20 mph what was likely to happen at 50 mph? I stopped the investigation with a clear understanding about the cause of the accident, and a good feeling too.
Example #2 I was retained to investigate the stability of a steep slope in an established residential area. Was it unstable and if so why?
Slope stability analysis can be expensive and time consuming. Lots of data collection, mathematics and number crunching. Engineers like this sort of thing but first, boots on the ground and a quick, inexpensive visual examination.
I saw that a retaining wall had been constructed at the toe of the slope. This would involve excavating the soil at the toe of the slope and possibly undermining it. But did it?
I saw cracks in the ground in back of the top of the slope – a telltale sign – so it did slide down, at least in the past. But, was it still sliding?
Examination of trees on the slope particularly saplings found that the trunks were curved, concave up-slope. The trees kept reaching for the sky like they do as they grow, while the ground beneath their roots kept sliding down-slope. No number crunching needed here; the slope was moving as I walked across it. I felt good seeing this, and also glad to get off the slope.
Conclusion: The slope was unstable and this was due to construction of the retaining wall.
Example #3 I saw the same curved saplings on another slope stability problem indicating the slope was still sliding. Not catastrophic fast sliding – not breaking-news fast – but sliding and unacceptable.
Example #4 Pie-shaped ground beneath a commercial building gave me that good soup feeling too.
I was retained to determine the cause of the foundation failure of a building. The foundations were still subsiding years after construction causing cracks in the concrete building. Precise surveys found 0.4 inches per year 10 years after construction. Not a lot but too much for a concrete building.
A geotechnical investigation of the building site found that it was underlain by a pie-shaped soil and rock fill. A few inches deep at one end of the building, 25 feet deep at the other end. The surface of a fill where foundations are placed subsides according to fill thickness. More where it’s deep and less where it’s shallow. And if it’s still settling after 10 years it means poor compaction during fill construction as well.
Strengthening the fill with cement grout fixed the problem. None of this was inexpensive, but the forensic investigation was simple, determination of cause certain, the fix successful and the feeling good.
Example #5 I was retained to investigate the condition of a nail gun involved in a bloody accident. Simple examination of the gun found no worn parts. I was about to retain experts from away in the design and manufacture of nail guns when I decided to have the injured worker re-enact the accident. He did this and I got video from three different angles with a simple iPhone and texted it to my client. We talked about how the accident might have happened based on the re-enactment and that was enough. It was a simple forensic investigation that ended quickly and it felt good.
I can cite other examples but that’s enough.
My frugal Mom would be proud of me hearing the penny drop, recognizing that the forensic investigation had determined cause sooner than expected, and saving money.