I continue to be excited about using drone photography during forensic investigations.  The engineer and former land surveyor in me loves the wealth of accurate data in photographs taken a few 10s to 100s of feet above a site where a structure failed or a person was hurt.

We’ve always had photogrammetry in engineering – using photographs taken from airplanes flying many 1,000s of feet above the earth to identify and measure features on the ground.- but we get more and better data from drone photos and get it quicker and cheaper.  The potential uses are something else:

Use #1: Investigating traffic accidents: An engineering colleague routinely sends a toy drone aloft, a 100 feet or so, and takes a photograph of a traffic accident site that he is reconstructing. (Ref. 1)  He sees his site from this angle right away and it guides his investigation as he does his field work.  He can also get a print of his drone photo for his engineering report..

Use #2: Conferring with clients: I conferred with a client a few months ago while both of us had a CD of aerial video of his property uploaded on our computers.  I had mailed the CD to him a few days earlier.  He commented on features on the ground relevant to my investigation of his failure.

In one case he gave the history of the ground at one location – cows drank from a former dug well there in the past – that was important in confirming the depth to the ground water beneath the site.  At the time I couldn’t quite believe what i was hearing about the cows and the dug well – there was no evidence of this when I was on site..

Use #3: Getting data on a site: I emailed a drone photograph to a client recently and asked him to identify the location of buried structures on his property.  Structures like two underground fuel oil storage tanks (USTs), – which leaked oil in the past – a drilled water well, two dug wells, a septic tank and a disposal field.  He did this then emailed the marked up photograph back to me a few hours later.  He used Paint, a program on PC computers.  It was all so quick and inexpensive.

Use #4; Getting BIG Data:: The height or altitude of the drone above the ground when a photograph was taken has always been of interest to me.  Robert Guertin, Halifax who takes my aerial video, found a program that gives a wealth of data on each photograph.  The data includes the height of the drone when the photograph was taken, angle of the photo shot below the horizon, bearing of the view with respect to North and the GPS location, all important data in forensic work.

Use #5: Getting low cost data:  I get the scale of drone photographs now from the known size of objects in the photographs.  Like the length and width of a building or the distance between the lines on a highway.  The scale of the photograph I sent to my client a few days ago that he marked up with Paint is 1″ = 40′.

I can check the scale of a drone photograph by setting out ground control before taking drone photographs, like photogrammetry-of-old.  Ground control is nothing more than points set out on the ground a known distance apart and height above sea level.  I used sheets of white paper to mark points on a site I was investigating in Cape Breton.

Use #6: Photographing hard to get at damage: I recently suggested to a firm who needed an expert that we could record the condition of a damaged wall with a drone photograph.  Later I could measure and analyse the damage in detail and get an idea of the cause – measuring like I do now of the ground but of a vertical surface rather than a horizontal surface.  No step ladders, staging, labour and lots of expensive time needed.  .

Use #7 Replacing expensive site surveys:  The drone photograph with a known scale is certain to replace the need in the future for a site survey by a land surveyor, and be far more detailed, less expensive and quicker.  Site surveys measure the size, location and elevation of objects and features on the ground.  Conventional site surveys can be time consuming and expensive.

Use #8: Seeing a site in 3D: I’m working with Robert to see if we can get a stereo pair of drone photographs of a failure site and using these to view a site in 3D like we’ve always done in photogrammetry-of-old.  Software likely exists now for viewing drone photographs in 3D.  If it’s out there we will find it and I will use it during my forensic investigations.  In the meantime we’re trying to do it ourselves.

(A stereo pair are two photographs overlapping by about 60%.  When viewed with a stereoscope – sort of like eye glasses – the site appears in 3D)

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What more do you want from simple drone photographs?  Name it and the potential for getting it.is almost guaranteed.  Honestly, with all due respect, you or your expert would be remiss if you did not get drone photos of your site.  Your expert would not be conforming to the changing forensic investigative standard of care.

Reference   

1.  A kid’s toy drone can photograph the site of an engineering failure, a personal injury or a traffic accident.  Posted September 12, 2018

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Take your pick: An expert from the great majority represented by Ruth Corbin’s pilot study of 152 experts, or an expert from the fringe, (Refs 1 and 2)

The study found that the majority of experts know they’re serving the court, not the lawyer who retains them nor the lawyer’s client, and they continue to swear oaths to that effect.  The study was carried out because the judicial system continues to disbelieve them.

Fringe experts believe they are serving the lawyer and his client, not the judicial process.  This to the extent that some want to know upfront the technical issues as perceived by the lawyer – no mention of technical issues that the expert might identify – and how much budget money they got.  These questions during a first telephone call don’t resonate well.  I wouldn’t call these experts hired guns USA style but perhaps treading close Canadian style.

The “two solitudes” came to mind when I was chatting with one fellow and this fringe characteristic was reflected in his comments when the question of who we serve came up..  When i asked he was adamant that experts serve the lawyer not the judicial system.

Fringe example #1: Later this chap asked me to join him in responding to a lawyer’s need for an expert to investigate the cause of damage to a structure.  I didn’t think much about it at the time but he only casually referred to the lawyer by his first name as someone he knew, briefly mentioned another party involved and identified the location of the structure.

Based on my colleague’s description of the problem as he was briefed by the lawyer the cause was obvious, an easy initial hypothesis.  I had investigated this type of problem often enough over the years and it’s written up in forensic engineering guidelines on typical civil engineering failures and their cause.

i agreed to join him help resolve the dispute.  He would manage the case he said and I would investigate and confirm the cause of the problem.  He asked and I updated my CV over a weekend and sent it off to him on the Monday, only to learn he had responded to the lawyer on the Friday sans my CV but including his.

On reading his response to the lawyer I saw brief mention of my name.  When I asked he said he would send my CV when the lawyer asked for it.  I also asked several times over the next few weeks for a copy of his CV as presented and the name of the lawyer and his firm but he never gave me this information.  Months later he explained, “With deference, I’m not going to give you his name.  He called me.”.  Tricky, eh?

He’s heard nothing since from the lawyer.  I can’t help but think the lawyer’s smart enough to know my colleague’s engineering background hardly qualifies him to investigate this type of failure.

Nor can I help but think I witnessed fringe behaviour.  This chap is pleasant, well educated and experienced and I’ll consider working with him in the future, for the benefit of the judicial system, but he’s a bit tricky as I learned and we’ll get things out in the open at the get-go.

But, on second thought, I don’t know if perception is everything and I’m seen to be associating with a tricky, fringe expert.  Another forensic engineering colleague on recounting this case to him was quick to remind me of the perception issue.

Following are a few more fringe cases to ensure that you know there is a fringe solitude to expert services.

Fringe examples #2 and #3: I read two expert engineering reports by separate experts, one on the stability of a fill slope and the other on a slip and fall accident.  I cringed at the bias exhibited by the phraseology in both cases in favour of the experts’ clients.  Crass in one case.

You might say there’s a subjective element in an assessment of bias and that’s true.  But I feel more confidant in my subjective assessment after reading about the eight main biases in engineering. (Ref. 3)

I’ve also read and written a lot of engineering reports, research papers and blogs/essays over the years and I sure do know the difference between objective and biased phraseology.  Think most of us do.

I’m also comfortable with the objective evidence in both cases.  In the fill slope case, the expert did not get out of his car to see the large pieces of construction debris at the toe of the slope threatening the stability.  The debris included organic matter like tree stumps that rot away in time and cause a slope to subside a lot.

And in the case of the slip and fall accident, quite apart from his phraseology, the expert’s comments indicated he did not know the standard of care existing in the area for investigating the skid resistance of the floor at an accident site.

(Skid tests are coefficient of friction tests like in high school physics)

(A fill slope is the slope the surface of the soil or another material slumps down to when it’s piled on the ground.  A cut slope is the slope soil takes when we cut into or excavate the ground.  We see cut and fill slopes everywhere along our highways)

Fringe example #4: Would you like to know about a second slip and fall accident that exhibited fringe behaviour?  But, to cut the engineer some slack, possibly because he was new to the expert services arena.

An engineer, a five hour drive from the accident scene, decided the cause of the accident from pictures provided by his client.  He did not travel to the accident site and examine it firsthand nor carry out skid tests.  That would have added to the cost of the forensic investigation.  The judge dismissed the expert’s evidence.

Fringe example #5: Would you like a fifth fringe case; actually a fringe expert?  At least to some extent a fringe expert.  Years ago I heard an expert remark that he “…knows how to work a case up”.  Work it up into a “…juicy case…”.

Is my years-ago colleague practicing near the fringe?  Possibly.  He is good though in his area of expertise and still practising suggesting he’s impartial enough.  The last thing a lawyer wants is an expert that can be made a fool by the judicial process.  My colleague would have gone by the wayside years ago if he was a blatant fringe expert.

There’s no question the great majority of experts serve the judicial system and do this objectively.  Read Ruth Corbin’s paper again.  And it’s no secret there’s a fringe element that serve themselves.

Sadly enough, with all due respect to civil litigation lawyers, some are contributing to maintenance of the fringe solitude.

I attended the Expert Witness Forum East in Toronto in February and gave a talk on the principles governing cost control in civil litigation involving experts.  During a presentation by others I heard a lawyer suggest that experts should be retained on a contingency basis.  That suggestion has got to be out in left field considering that perception is everything in the judicial process.

The suggestion went nowhere in the ensuing discussion.  But the idea is out there and I’m sure there are fringe experts who will pick up on this idea and run with it and help maintain the “two solitudes” of expert services.

Fortunately, the judicial system is getting what it needs from the great majority of experts, whether it realizes it or not.  The fringe just muddy the waters a bit.  Still, the system has got to be on guard against the fringe experts scaling the bulwarks and taking over.  The fringe experts are out there.

References

1. How experts are helping break the expert witness logjam.  Posted April 30, 2018 (A blog on Ruth Corbin’s  paper, following)
2. Corbin, Ruth M., Chair, Corbin Partners Inc. and Adjunct Professor, Osgoode Hall School, Toronto, Breaking the Expert Evidence Logjam: Experts Weigh In, presented at Expert Witness Forum East, Toronto, February, 2018 (Google it)
3. Are experts being being broadsided by bias, unbeknownst to them?  Posted April 12, 2018