Used to be the Alaska State troopers used licensed Surveyors to do necessary survey work. I worked on a couple of these crime scenes many years ago. But now the Alaska State troopers use their own measuring techs. I have watched these guys a couple of times. They did not seem to know how to use the equipment and it was almost scary. I tried to talk to one of these guys, politely mind you, just to get a feel for how much he knew about the data being collected. Almost got arrested for asking.........we were working near a crime scene and I waited till he was packing up his equipment. Using a layout rod with a large prism within 3 to 5 feet of the instrument was shocking.  How did they orient the shots being taken with no basis of bearing, centerline shots, edge of road shots, ect. Nope they did not tie any of that. They tied their paint marks, and left the cans in the ditch, and that was that. Maybe they were given a crash course in data collection I don't know, but if I was a lawyer defending someone I would question the precision of the survey!