Reaction time may be factor in officer shootings when stories, facts don't jell

Police • Law enforcement personnel learn that fractions of a second can make a big difference.
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The factors that justify or cast doubt on an officer-involved shooting can come down to hundredths of a second: a turn of the head, a few extra inches in the draw of a gun, the slightest distraction.

Measuring reaction time — and finding ways to improve it — is the goal of the Force Science Institute, which was conducting its second annual two-day seminar with Utah law enforcement officers on Tuesday and Wednesday.

More than 200 local, state and federal officers attended Tuesday's session on the heels of a spate of officer-involved shootings statewide.

As shootings are reviewed, investigators and prosecutors should consider the limits of reaction time and attention span when officers' stories don't align with the physical evidence, said Bill Lewinski and Chris Lawrence, researchers with the Minnesota-based Force Science Institute.

For example, an officer may claim to have fired on a subject as the subject was threatening the officer. But the autopsy shows the subject was shot in the back of the head.

That doesn't necessarily mean the officer is lying, said Lewinski, institute director. The officer requires more than half a second to react to the initial threat and draw the gun; within that time, the subject could have turned around to flee. But that may not leave the officer enough time to react to the change in the threat; studies show reversing his decision to shoot likely takes longer than the time to pull the trigger, Lewinski said.

"It's a dynamic interaction," Lewinski said.

The ability to nimbly react to changes in a situation all comes down to attention span, Lawrence said.

"The limit of our attentional resources is what really drives these situations," he said.

That may explain an officer's failure to account for every factor at a scene; even critical action by fellow officers can go unnoticed if the officer is focused on a threatening subject.

"We expect officers in a life-threatening situation to afterward be able to tell us, 'Where were you standing? ... What were the other people in the environment doing at that time?'" Lawrence said. "We don't know what we don't see."

The second-by-second data on physical and mental responses can help officers prepare for deadly confrontations, said Salt Lake City police Sgt. Shawn Josephson.

"The way you train really does have an impact on the way you react," said Josephson, who shot and killed a suspected drug dealer in 1996 and coordinated his department's peer counseling for several years. Whether officers prepare for specific scenarios or just improve muscle memory in firearms, saving fractions of seconds or tiny amounts of mental energy can improve responses.

"It can't prepare you for everything, but it can better prepare you," Josephson said.

The Salt Lake County district attorney's office is sponsoring this week's training as District Attorney Sim Gill pushes for changes in how officer-involved shootings are investigated. Gill has proposed an inter-agency task force to investigate such shootings. Shootings now are investigated jointly by prosecutors and the officers' own agencies.

Utah law enforcement officers have fired on at least five people in the past five weeks. Two people were injured, two were killed and one was not struck by any bullets. —

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