There have been several serious car crashes in Sioux Falls in the past couple of weeks. These days law enforcement use state-of-the-art sophisticated equipment to reconstruct a crash.
"Twenty years ago we used to use a 200-foot tape measure and lay them out on the pavement and do the markings that way," Lt. Troy Lubbers of the Sioux Falls Police Department said.
Not anymore. Today, Sioux Falls police use a prism stick along with an infrared laser that work together gathering crucial information.
"It's got GPS coordinates in it, so whenever we mark the pavement with the prism, it goes out and gives us a GPS coordinate, elevation, so it's very accurate," Lubbers said.
Once the data has been gathered in the field, it's brought back to the police station and then plugged into a computer.
A computer software program then maps out the crash scene in 3-D. It shows every marking the police made on the pavement.
"Primarily what our goal is, is to find out what happened in the crash," Lubbers said.
In almost all cases, police need to determine the rate of speed.
"How far it traveled, so many feet per second and plug that into a formula to say that the vehicle traveled X amount of feed in this amount of time, so then we can determine that speed from the formulas," Lubbers said.
All that evidence can then be given to prosecutors for possible charges. But it's not the only reason reconstructing a crash is so important.
"The other part of it is to explain to the families if they lose a loved one or someone gets seriously injured, we want to be able to go back and tell them this is why the crash happened," Lubbers said.
The information gathered can also be given to City traffic engineers to see whether there adjustments need to be made to traffic lights or street construction.