New Study Explores Threats Posed By Prone Suspects

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One of the most dangerous positions a suspect can assume on the ground is prone with his hands tucked under his body, either at chest or waist level. What’s hidden in those hands? And if it’s a gun, how fast can he twist and shoot if you’re approaching him?

This month [1/09], the Force Science Research Center, in cooperation with Indiana University and the Northeast Wisconsin Technical College, will launch the first study of its kind in an effort to clearly define your risk and, hopefully, identify your best approach tactics in dealing with this common street problem.

The results may also help explain to civilians why officers sometimes react with what may seem like exceptional violence when trying to control a downed offender whose hands are concealed beneath him.

“When a prone suspect resists showing his hands when an officer orders him to or attempts to pry them out, officers become very suspicious and fearful about what his motive is. And justifiably so,” says FSRC’s executive director, Dr. Bill Lewinski. “FBI research has shown that suspects with concealed weapons most often carry them to the front of their bodies. So, when prone, they may have easy access to a weapon or already be holding one.

“Until the hands are controlled, officers are very vulnerable in this circumstance, and they often use a fairly high level of force to gain control of the hands because of their concern. They may deliver strikes with batons or flashlights that to naïve civilians watching a video clip on TV may look like malicious outbreaks of rage and vindictiveness.”

Since its beginning more than 4 years ago, FSRC has conducted a series of ground-breaking time-and-motion studies, documenting the amazing speed with which suspects can attack from a variety of positions—turning and shooting while running, drawing and shooting while seated in a vehicle, and so on.

“The prone study is an important extension of this sequence,” Lewinski explains, “and is expected to further pinpoint the formidable reactionary curve that officers are behind when attempting to prevent or respond to potentially lethal assaults.”

Several months ago Lewinski conducted some rough preliminary testing on prone action times at the FSRC lab at Minnesota State University-Mankato. Role-playing a prone, armed offender with hands tucked under his body, he repeatedly turned to present and fire a gun as if shooting at a contact officer approaching him from the feet or side. A time-coded video camera recorded his movements. You can view a short video clip of the movement here: https://www.forcescience.org/video.html

The average time it took him to make his threatening moves was “about one-third of a second,” Lewinski says. “This speed would likely be faster than an average cover officer could react and shoot to stop the threat, even if the officer had his gun pointed, his finger on the trigger, and had already made the decision to shoot. In other words, the officer would stand little chance of being able to shoot first.”

This convinced Lewinski that the subject was worth a much more in-depth investigation.

The core research will begin Jan. 5 at Northeast Wisconsin Technical College in Green Bay, with the assistance there of Erik Walters, public safety training technician.

Four cameras positioned at different angles will film 7 volunteer role-players with different body types moving in a variety of ways to present a gun from under their body and shoot at an approaching officer. “The subjects will be young—reflecting the age demographics of offenders most likely to assault police officers—and agile,” Lewinski says. “Agility may play more of a role with suspects who are prone than with those in other shooting postures.”

Three of the cameras will be high-speed video units purchased by NWTC with a State of Wisconsin grant to assist with FSRC research. Walters used one of these to record the preliminary tests at Mankato.

The fourth camera is a sophisticated SportsCam, used by high-level athletics coaches and researchers in biomechanics, recently purchased by the Ergonomics Laboratory at Indiana University in Bloomington. This unit can film in color at speeds up to 500 frames per second.

FSRC learned of this equipment through a graduate student, Madeleine Gonin, originally from South Africa, who works in the IU Ergonomics Lab and is pursuing a PhD in human performance and ergonomics. Her master’s, however, is in safety management, with a focus on workplace violence. “There’s a high level of crime in South Africa, and I want to help find strategies for reducing it,” she told Force Science News.

An accomplished martial artist, she became an instructor in the Rape Aggression Defense system after arriving on campus, and through that involvement developed friendships with IU campus police and officers with Bloomington P.D.

As a subject for her PhD dissertation, “I was looking for a program that fitted in with violence prevention,” she says. “Some of the officers I knew suggested I get in touch with the Force Science Research Center.” She hopes to base her dissertation on the prone action-time research.

Gonin will be in Green Bay, along with Charles Pearce, project director at the IU Ergonomics Lab. To supplement what’s filmed there, they will photograph more subjects making more threatening movements on the Indiana campus, using student volunteers, including participants in a cadet program run by the university police department.

Using the Lab’s advanced technology, under supervision of director Dr. John Shea, a professor in IU’s Department of Kinesiology and Gonin’s academic advisor, the researchers intend to convert the photographic images into animated figures.

With cutting-edge software and a link to an immense databank of human forms, they can adjust the figures to as many different height, weight, and strength specifications as they like, and measure the movement times of each in the various action patterns.

“Without a doubt,” says Lewinski, “this will be the most thorough and complex analysis of human movement ever performed for law enforcement research.”

The initial goal is to nail down action times precisely—just how fast can a prone suspect present a deadly threat. “People tend to underestimate how quickly a human being can actually move,” says Gonin. “They also tend to underestimate how slowly officers react when they are under stress and narrowly focused.”

Beyond those measurements, the researchers will also be searching for early indicators that could telegraph that a suspect is initiating a dangerous movement. Ideally, this analysis will identify certain cues officers could watch for in prone-suspect situations. “We don’t know if we’ll be able to find these cues, but we’re going to look for them,” Lewinski says.

And finally, there may be findings that could affect training and tactics. Does approaching straight-on from a prone suspect’s feet, for example, offer the best protective edge against sudden threatening movement, as Lewinski suspects may be the case?

Lewinski estimates it will be a year or more before a final analysis is available, but IU’s involvement in the project represents an important breakthrough beyond the critical street knowledge that may result.

“One of our major goals at Force Science is to stimulate interest at universities and other influential institutions in doing research that is of value to line officers,” he says. “There has been a huge hole in research into issues that can help street officers perform with improved skill and safety. This is a step toward filling that gap. What a great way to start the New Year!”

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