Getting maximum value from video of a controversial use-of-force encounter may require more than just viewing raw footage as it comes from the camera. In fact, three extra steps are often the keys that allow investigators and other interested parties to unlock critical secrets “hidden” in recordings that may not be evident at first glance, according to Dr. Bill Lewinski, executive director of the Force Science Institute.
Lewinski itemizes these as part of a new block of instruction on body cameras that’s now included in the certification course on Force Science Analysis. They will also be explored in the wealth of unique instructional material in the special two-day course on body cams coming up at the Force Science Training Center in November. (That course is sold out but due to enthusiastic demand repeats are being scheduled and will be announced soon.)
“To fully understand the human dynamics and an officer’s decision-making in a force incident you may need to take video apart frame by frame,” Lewinski says. “That’s true whether the footage is from a body camera, a dash cam, a security camera, a camcorder, or a cell phone. In fact, the more video you have from different sources, the better off you may be.”
Here’s the procedure he recommends:
- Determine the frame rate. Video, which appears to record a continuous stream of action, is really a series of snapshots taken at timed intervals that vary radically among camera types. “Some dash cams film at 8 frames a second, some security cameras at 4 frames a second, body cams at about 30 frames a second–or a different snapshot every 1/30 of a second,” Lewinski explains.
“When it comes to force dynamics,” he says, “split seconds matter.” Cameras with slow frame rates, for example, may actually miss recording critical moments of action.
In one case Lewinski analyzed, an officer was accused of excessive force for throwing an arrestee against the side of a car. The officer claimed the suspect tripped him, causing them both to fall against the vehicle. The security camera that captured the action recorded at only 4 frames a second, and Lewinski was able to establish from a second camera positioned at a different angle but also recording at 4 frames a second that the flick of the suspect’s foot tripping the officer was fast enough that it occurred between frames and thus was not caught on the first camera.
“Knowing frame rates is also essential for accurately syncing footage from different cameras,” Lewinski says. Computer programs are available for establishing speeds when camera ratings are unknown and for double-checking manufacturers’ claims, he says.
- Time-stamp all videos. “Free computer programs that can be downloaded from the Internet will impose time-stamps on digital video to one-hundredths of a second,” Lewinski says. “When the recording is advanced or repeated frame by frame, the viewer can then more clearly see and understand just how incredibly fast action and reaction can occur in a force situation.
“A classic example is the mere flicker of time it takes a subject to turn from a face-on, threatening posture to a position of flight–much faster than an officer who had made the decision to shoot can possibly realize what has changed and prevent shooting the suspect in a different position. Being able to see that actually timed out on video can be a very powerful illustration.
“Time-stamping helps investigators analyze what happened in fractions of a second. We also strongly encourage that to fully analyze a video, key images be freeze-framed to clearly illustrate important moments and decision points.”
- Coordinate all available cameras. Time-stamping and frame-rating should lead to a syncing of images of an incident from all available cameras in a split-screen display. “Now,” Lewinski says, “you have the ability to view the same precise moments of action from a variety of vantage points, matched to fractions of a second.
“Lighting may differ from camera to camera. Blurred images on one may be clear on another. Differences in angle may be revealing.”
Lewinski recalls a case in which an officer was accused of smashing a suspect in the head with a closed fist. On poorly illuminated video from one camera, he looked guilty as charged. But other footage, synced frame to frame and benefitting from reflected light and a different angle, revealed that the officer actually had reached with an open hand to apply a cupping control technique to the back of the suspect’s neck. “With that,” Lewinski says, “he was able to challenge the accusation against him.”
In summary, Lewinski told Force Science News, “Working with video recordings can be very complex but they can be critical to properly interpreting a use-of-force event. The world captured by video is not necessarily the sum total of reality. Investigators of officer-involved shootings need to know how to maximize the benefits of this increasingly prevalent tool and avoid its pitfalls. That’s why we’re focusing special training on this important subject.”
Lewinski will offer more observations on video issues at the upcoming annual training conference of the Illinois Homicide Investigators Assn. On Oct. 21 he will conduct two three-hour sessions on “Force Science and Body Cameras,” which will explore critical technological and human performance factors to keep in mind when analyzing video footage as part of an OIS investigation.
The conference will be held Oct. 19-21 at the Westin Hotel and Conference Center in Itasca, IL, a suburb of Chicago. For more information, contact the association at: ILHIA@comcast.net or check the group’s website: www.ilhia.com