Collision course teaches crash analysis

Local patrolmen learn how to reconstruct accident scenes

By CHERY SABOL

The Daily Inter Lake

Witnesses are the least reliable source of evidence when an accident happens, but the co-efficient of friction doesn't lie.

Montana Highway Patrol troopers are trained in the physics and dynamics of accidents so they can determine what happened, even after the wreckage is cleared away.

Years ago, there was only one accident reconstructionist in Montana, said Capt. Clancy King of the local Highway Patrol office. He recently sent five of his officers to that level of advanced training in Helena.

David Mills, Jim Hawkins, Evan Schneider, Martin Shrock and Dustin LeRette all learned the intricacies of accident reconstruction.

Troopers spend 80 hours learning basic "at-scene" accident investigation in the patrol academy.

After three or four years, they usually go to 80 more hours of technical training - "the nuts and bolts" of accident reconstruction, King said.

Accident-reconstruction school is another 80 hours - graduate-level training for officers.

Troopers are expected to know the formulas and techniques that will point them to facts about a crash even years after the fact, King said.

Officers learn how to calculate a vehicle's speed, based on how far it flies if it is airborne.

They can determine how two vehicles came at each other and bounced off of each other after a collision.

The filaments inside a headlight bulb reveal whether a vehicle was driving with its lights on or off, signaling to turn or not.

Finding the point of impact is critical in any crash investigation, King said.

For a single-vehicle accident, investigators work backward from where the vehicle lands.

For a two-vehicle accident, the investigation goes both forward and backward from the point of impact, King said.

Measuring how far a pedestrian slid across the pavement can help calculate how fast a car was going when it struck someone. The distance an ejected bicycle or motorcycle rider slides can be used to determine his or her speed.

Teaching involves dry mathematical formulas. It can also include launching a semi truck off of a ramp and flinging raw chickens across various road surfaces.

"For geeks like us, it's pretty thrilling stuff," King said.

TECHNIQUES IN accident investigations are always changing, King said. Anti-lock brakes don't leave the skid marks their predecessors did. Newer, more flexible car bodies absorb energy better, so the old standards of looking at vehicle damage have to be updated.

Vehicles respond differently to crashes on asphalt, concrete or chip-sealed surfaces. King said there are more accidents in the winter, but injuries usually aren't as severe because vehicles collide and bounce off each other better on ice.

Things aren't always what they seem at an accident scene.

King recalls a fatal crash near Elmo that killed two girls and eventually sent a man to prison. The two vehicles collided in the man's lane of traffic. But troopers' investigations showed that he drove into the girls' traffic lane and they moved into his to evade him. He moved back and the result was fatal.

Years ago, on Conrad Drive, a vehicle went off of the pavement and rolled. But it landed facing backward. King investigated the crash and was confounded.

Another officer looked over the scene and found the answer. The vehicle had struck a guy wire and rotated around it, landing in the opposite direction. Striation marks that were visible on the vehicle once it was set upright showed exactly where it hit the wire and pivoted.

"That's one of the strangest ones I ever dealt with in reconstruction," King said.

He also had a crash near Echo Lake that proves the theory that witnesses aren't always reliable.

King believes that's because the details of an accident usually go unnoticed unless a driver attracts a witness' attention first. There's an exception, though, and that's adolescent girls.

Two girls and their father were outside playing basketball when a vehicle crashed. The accused driver said someone else was behind the wheel.

The father testified. He hadn't noticed much about the crash.

But the girls, in that prime age group of 10 to 13 that is acutely attuned to things such as what someone is wearing and what their hair looks like, hadn't missed a thing, King said.

"Those girls could tell which doors people crawled out of and what they were wearing," he said.

He's learned to keep an open mind during an investigation and to be guided more by physical evidence than be pushed by witness statements.

Physical examination that includes taking photos and measurements can take two to four hours at the scene, King said. Full investigation, including interviews, can take twice as long.

The simplest crash generates a simple crash report. An accident that involves lethal injuries can fill four to eight pages of narrative, King said.

It's detailed because it has to be. The report will the be basis for any criminal or civil actions that come later.

More than a third of his officers are trained now in reconstruction, King said.

Trooper Jim Hawkins is one of the five who graduated from the school in early December.

"It's a lot of math," he said.

By the time they were done, officers were well-versed in Newton's laws of motion.

Officers have programs that allow them to plug in known factors in an accident, such as distance and elevation to come up with answers to questions on speed and other elements.

But it's important for troops "to have a grasp on where those equations came from," Hawkins said, so they learn to do it without computer assistance, too.

"I don't know that I enjoy it," he said of the mathematical work. It happens to be crucial in his career now, though.

"As a kid, you wonder, 'When will I even use this?'" Hawkins said of math skills. "Why would I need to know this in real life? To do my job, you have to be able to do the math."

His instruction came from a Florida teacher from the Institute of Police Technology and Management, and a Canadian expert.

He hasn't had a full-blown reconstruction since he returned, but he's ready to do it when it comes up, he said.

"Besides being ticket-writers, we pride ourselves on our accident investigations," Hawkins said.

"It's certainly something that's interesting."

Reporter Chery Sabol may be reached at 758-4441 or by e-mail at csabol@dailyinterlake.com