Question, How many of you have had the opportunity to conduct an accident reconstruction survey? How does one get involved in this type of work?
Word of mouth. You have to get recommended by someone, usually. That's how it worked for me, anyway.
It's been many years since I did one. Your first bet would be to talk to attorneys that specialize in personal injury. They are the ones who would be using your "product". If you do go into this be sure and note EVERYTHING, I was asked what the color of a sign was that I had located. Skid marks, lane stripes, bridge bents, retaining walls, any vegetation that might block line of sight, profile(s), etc. Lots and lots of pictures and be sure to plot in color. Juries don't "know" the laws and sometimes are swayed by who puts on the best show. We once had two cases on the same accident (two different injured parties), one case was won and one was lost. Same data, same attorney, same accident - just different defense attorney.
Andy
One question, do you have a laser scanner?
In our area, you shouldn't expect to get asked to the dance without a laser scanner. Most policing entities have their own total stations and want the work themselves.
As said earlier you might call the personal injury attorneys.
> In our area... Most policing entities have their own total stations and want the work themselves.
>
Same here. There is specialized data collection software and desktop post processing software. (Carlson makes one.)
As LEO has come to see a bigger and bigger gulf between the "civilians" and LEO, they less and less want anyone else included in an investigation.
They become expert measurers in about a week long course, I think. Might be two weeks. But the measurement part is a portion of the course, from what I have heard.
I think my friend that did it said a surveyor did some of the training.
Andy has it exactly right. Expect the attorneys for the other side to nitpick every detail. I spoke with an Engineer who once developed a 3D simulation of an accident. He said one attorney questioned him at length about the particular shade of yellow he had used to create the lines that represented the centerline of the road. In the end the attorney made a motion to exclude the model and all testimony related to the model because the shade the engineer used was 2 to 3 shades off from the "official" DOT shade.
Did any of that have anything to do with the accident? Nope. Not one thing. But that attorney had nothing else to attack. In cases where you can't attack the message, you attack the messenger.
Larry P
"reconstruction" might not be the right word. Reconstructionists (if that's a real word) are experts in skid-mark analysis and impact stuff. By "impact" I mean something like what a vehicle weighing a certain amount and analyzing that impact on a guardrail or utility pole or another vehicle or perhaps a pedestrian and how far they flew before landing.
I would think a surveyor would just be there to map the scene after the incident. An "after action report" for lack of a better phrase.
The only surveyor I know with anything close to this kind of thing got called out on two different homicides. How he got called is a mystery to him. One case he told me about, they had left the body where it lay and all the shell casings they had located. He had to map every little detail including orientation of the body and the bullet holes. He didn't really have a clue what to do but investigators told him what they wanted mapped and such.
I've come across a couple of accidents not long after they happened and the highway patrol had their own total station out mapping stuff. I saw both accidents coming home from work in Asheville, NC just north of town. (Larry P. knows where I'm talking about.) One was really bad and had multiple fatalities. After about an hour, I finally eased on by and it was really bad. Kind of rattled my cage. To clarify: I didn't actually witness the accident - just the after-math.
In any event, I hope you have a strong stomach. Never know what you might get called for. My step-dad is a pathologist (now retired) who at times or another was also the local medical examiner and county coroner. I've been with him a few times on these calls and it's something I wish I could forget.
Laser scanners are all fine and stuff, but they can't show detail like skid marks or pick up tiny details like a .38 or .25 shell casing or a bullet hole in a body. That kind of detail will still need a total station.
But, to get your name in the hat, contact the local chief of police or the sheriff's office or the nearby state patrol post HQ.
That's my 2 pence - maybe I should call it an even "quid" given inflation.
E.
"Laser scanners are all fine and stuff, but they can't show detail like skid marks or pick up tiny details like a .38 or .25 shell casing or a bullet hole in a body. That kind of detail will still need a total station."
Uh, they sure can.
Laser scanners are all fine and stuff, but they can't show detail like skid marks or pick up tiny details like a .38 or .25 shell casing or a bullet hole in a body. That kind of detail will still need a total station.
Really? A Laser Scanner can't but a total station can?
> "Laser scanners are all fine and stuff, but they can't show detail like skid marks or pick up tiny details like a .38 or .25 shell casing or a bullet hole in a body. That kind of detail will still need a total station."
>
> Uh, they sure can.
Perhaps I'm wrong. I would just think something that small would get lost in that point data.
> Laser scanners are all fine and stuff, but they can't show detail like skid marks or pick up tiny details like a .38 or .25 shell casing or a bullet hole in a body. That kind of detail will still need a total station.
>
> Really? A Laser Scanner can't but a total station can?
Like I said, Perhaps I'm wrong.
I meant a TS shooting at someone holding a prism. Not just the TS by itself.
>
> Like I said, Perhaps I'm wrong.
> I meant a TS shooting at someone holding a prism. Not just the TS by itself.
Yes you are definitely wrong, a Laser Scan combined with High Definition panoramic photos taken by the Scanner is no comparison to a total station or 2 total stations with 4 guys or 3 total stations with 6 guys ............etc...etc...etc......
I believe what he meant was that very defined points can be "pinpointed" at the scene with conventional total station as opposed to "extracted" from post-processed point cloud data.
"Laser scanners are all fine and stuff, but they can't show detail like skid marks or pick up tiny details like a .38 or .25 shell casing or a bullet hole in a body. That kind of detail will still need a total station."
Our firm has used laser scanners to pick up skid marks, road paint stripes, cracks in the asphalt, crumple zones, oil pools, coolant pools, blood pools, blood splatter, debris fields, etc.. I am POSITIVE a laser scanner can pick up a shell casing.
Simply placing a long slender dowel rod in a bullet hole prior to laser scanning is one way to show bullet trajectory.
Our Z+F laser scanners can pick up the pores and hair follicles in your skin. I wouldn't contemplate using a Total Station over a Laser Scanner for accident reconstruction.
Skid marks! Really? I would never have imagined it could make out a dark black mark on semi-black, i.e. sealed asphalt, surface.
Can they see color differentials?
Guess, I've been completely wrong the whole time!!
My apologies if I offended any of you scanner buffs out there.
Since you mentioned blood spatter: can it "see" different spatter types such as a falling drop (like from a nose bleed) as compared to something like being flung off of blunt object like a hammer? Think homicide investigation.
I'd like to see that. No sarcasm at all. Honestly, I would like to see that.
Do you have something you could show us Richard? I find forensics really interesting. To me it's just another form of puzzle solving.
E.
How are the policing entities measurements admissible ...they are not surveyors ...
"...I would never have imagined it could make out a dark black mark on semi-black..."
Laser Scanners bounce their laser off a surface. The intensity of the return is dependent on texture, but primarily color; both affect the albedo. That being said, a laser scanner can tell color differences.
Andy
"Juries don't "know" the laws and sometimes are swayed by who puts on the best show."
I would strike the word "sometimes"...
"How are the policing entities measurements admissible ...they are not surveyors ...:
In the State of Arizona they do not have to be surveyors...