Police using science to reconstruct fatal crash

Sharna Johnson

Reconstructing a vehicle crash is pure science, according to Police Chief Steve Sanders.

Officers trained in crash reconstruction start with the result and investigate by working backwards, performing a series of measurements and calculations, said Sanders.

Typically used by police in serious crashes, a reconstruction can mathematically map out what happened leading up to a crash second-by-second, illustrating how things came about, Sanders said.

Clovis police are investigating an officer-involved crash Wednesday resulting in the death of a 56-year-old Clovis woman and left a 40-year-old Clovis woman in critical condition.

Family members said Mary Castillo died of her injuries at a Lubbock hospital around 2:30 p.m. Thursday.

Sanders said he has absolute confidence in his crash investigators and believes their team approach brings shared responsibility and expertise to the case.

Not concerned about perception of a conflict of interest, he said the process is science and can hold up to scrutiny.

“It’s our responsibility to make sure that we do quality investigations and that’s what we’re going to do with this one,” he said.

“People need to put their biases aside that we’re going to hide information. Once the investigation’s complete, anybody’s got the opportunity to come in and get a copy of the case and scrutinize our work. I think they’ll be surprised at how thorough we are.”

The Clovis Police Department is responsible for the jurisdiction the crash occurred in and is the best suited for the job, he said, explaining state police were busy the night of the crash with another crash investigation north of town and it might have taken hours to bring in a crash team from the northern part of the state, possibly compromising evidence.

“It’s unfortunate it was a police car that was involved,” he said. “But if the accident happened between two other vehicles, we’d have the same type of response to the crash.”

Sanders said preliminary information indicates Officer Stephen Gallegos, on routine patrol at the time, caused the crash when he failed to stop at a stop sign at Grand Avenue and Sycamore Street.

Gallegos’ duties have been curtailed and he is restricted to police headquarters during the investigation.

The department’s Technical Accident Investigation Team, a crew of nearly a dozen officers, is trained, Sanders said, in using nationally recognized mathematical formulas developed by experts in mechanical physics.

“It’s extremely accurate,” he said, explaining a reconstruction usually determines the speed of the crash within a margin of 1 to 3 mph.

“We all know that there’s physics involved in the crash,” he said.

“Weights and speeds coming into the crash have to equal the weights and speeds after the crash (or) momentum.”

Sanders, who has 20 years experience as a traffic officer, said he has done many reconstruction’s himself and is qualified to testify as an expert.

Reconstruction is a time consuming process that can take anywhere from a few days to weeks.

And he said investigators use the information collected on scene from gouges in the road, to skid marks vehicle damage and final resting places, to do calculations that are then turned into a series of drawings showing the placement of the vehicles at different intervals and an animated movie that shows the event in motion.

Time and distance analysis can even show what drivers were seeing —whether obstacles were blocking their vision or if other factors interfered — in one second increments as they draw closer to the impact.

“It gives you a pretty good perspective of what happened and then it gives you an opportunity to go back and revisit with the drivers,” he said, explaining reconstructions are combined with traditional investigation methods such as witness interviews and evidence collection.

In a courtroom and civil cases, Sanders said reconstructions are relied on heavily to assist in determining fault in crashes.

And because of the scientific and mathematical basis, “it’s a completely unbiased look,” at a crash, he said.

Sanders said though the process can be accomplished by one officer, but by using a team, as with Clovis police, it is completed faster and more eyes on a case translates into cooperative opinions and checks and balances.

“As a team, everybody gets a piece of the responsibility,” he said.