Animated Crash Scenes Can Often Give More Complete View, Understanding
Of Events Preceding Collision
Patrol officers driving separate cars in Eugene, Oregon one day answer
a call about an armed robbery/kidnap suspect, and, after locating him,
embark on a wild pursuit through the city’s streets at high speeds.
One of the patrol car’s drivers tries to stop the vehicle chase
by performing a so-called “Tactical Vehicle Intervention (TVI),” essentially
blocking the suspect’s car with his own. The TVI works—temporarily—as
the suspect regains control of his vehicle. The suspect then tries to
speed away, directly into the path of the primary pursuing patrol car.
The two cars collide head-on, and , although no one is injured, the suspect
flees on foot. When the suspect pivots toward an approaching officer,
the officer shoots him. Amazingly, the suspect continues to flee. By
now, a detective unit has arrived on the scene and catches the suspect
as he crests a small embankment.
With such a huge and complicated scene to map and diagram, a single
scaled diagram, even with the best of details, may not be sufficient
to fully show all of the frenzied activity involved between the officers
and their suspect. In this instance, therefore, an animated depiction
of the scene probably would give a more complete representation of the
sequence of events.
Build Animations in PowerPoint
Although not used widely among reconstructionists today, the practice
of animating selected collision scenes is gaining momentum. Basically,
animation allows for the presentation of a scene or situation in near
real-time motion. Traditionally, crash animations, or “movies,” were
created by professional firms who specialize in using expensive and difficult
animation software. These specialized animations also come with a very
high price tag ($30,000 to $60,000 is not uncommon). Obviously, this
type of expense is just not in the budget for most investigations. A
more economical way to create an animation is to use a software program
already available on most computers today, such as Microsoft PowerPoint.
With a little experimentation, an investigator can save a series of 2D
or 3D slides from his diagram program and combine them in PowerPoint
to create an impressive animation.
Example
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PowerPoint Slide 1 |
PowerPoint Slide2 |
PowerPoint Slide 3 |
PowerPoint Slide 4 |
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Result of 4 PowerPoint slides
converted to an animated GIF in Adobe Image Ready (.5 sec frames) |
A PowerPoint animation can show a sequence of screen shots of a vehicle
moving to impact, and then to the post-impact moment. It is this sequence
of events, including tire mark evidence, that can lead a judge and jury
or other parties to understand how the vehicles interacted and moved
to their final rest position.
“Many people will do a diagram of a scene as it looked when they
got there.” Says Duane Meyers, an accident reconstructionist and
trainer with the Wisconsin State Patrol and Great Lakes Crash Analysis,
LLC. “That’s what they put into their reports, or print out.
That’s fine. It’s forensic evidence to show where the evidence
was,” Meyers explains. “But it doesn’t necessarily
tell a person how this whole event happened.”
When there is a high uncertainty about the events within an accident,
or the scene is so complex that just one reference point—the point
where the cars have come to rest after impact—proves too limited
for a complete understanding of the scene, Meyers and other reconstructionists
like him feel animation can help. To accomplish animation, the reconstructionists
first must develop a series of illustrations in his narrative report
that outline the sequence of events. The sequence needs to show how the
vehicles moved toward impact, where they came from, how they interacted
over the crash site, and, eventually, came to final rest. Once this sequence
is developed, the reconstructionist can use Microsoft PowerPoint to illustrate,
frame by frame, all of the events.
“It’s up to the individual as to how close, in time increments,
he wants each frame to be. Obviously, the closer the time element, the
smoother the animation will look,” said Meyers, who uses, and teaches,
The Crash Zone diagramming program available from The CAD Zone, Inc.,
Beaverton, Oregon. The Crash Zone, like some other drawing programs,
allows users to export images of the collision diagram to a format that
can be incorporated into a PowerPoint animation.
To view a streaming video of a PowerPoint presentation, click
here
Build Animations in a Video Editor
In addition to Microsoft PowerPoint, illustrators have the option of
taking images created in The CAD Zone software and copying them to a
video editing program such as Pinnacle Studio, Adobe Premiere, and Avid
Xpress DV. They can create the movie in real time or at any speed of
their choosing. Standard video in the United States is typically developed
at a rate of 30 frames/second. This results in a smooth looking movie
without any jerking movements. However, this high frame rate is not absolutely
necessary. A video created with 15 frames/second can look quite acceptable.
The key to successful admission of illustrations in trial will oftentimes
depend on the accuracy of the illustration relative to time and distance
parameters. This applies to whatever form in which the presentation is
given.
Animation Gives ‘Sequential’ View
Detective Sergeant Randall Tanghe, of the Hilltown Township P.D. in Pennsylvania,
and also a professional reconstructionist, agrees with Meyers that animating
vehicle crashes can often clarify scene details. “By bringing an
animated crash scene into the courtroom,” contends Tanghe, “the
reconstructionist must be able to quantify forensically every still image
within the animation. In a courtroom presentation, the recontructionist
is demonstrating to the judge and jury a sequential approach of both
vehicles based upon what they actually did versus what they could or
should have done had both vehicles’ drivers been doing the speed
limit,” Tanghe said.
Helpful for Near-Miss Accidents
Why are animated presentations of crash scenes so helpful, even critical,
especially in court? As one example, near-miss accidents, which are quite
prevalent in cases a reconstructionist encourters, can be best explained
through an animated sequence of events from the crash scene. “If
the defendant had been doing the speed limit as opposed to, say, a calculated
speed of 15 mph over the limit,” Tanghe explains, “we would
be able to better show by animation that a driver would have had additional
time, and distance, to clear the area of impact. Therefore, no impact
would have occurred,” said Tanghe. The animation, he continues,
will visually demonstrate the near-miss accident. “It will show
the viewing audience the sequence of events as they unfold, and exactly
what would have transpired had the speeding vehicle been traveling at
the speed limit, as opposed to what actually occurred as a direct result
of the excessive speed,” Tanghe said.
In addition to using animation for crash scene diagrams in his professional
work, Tanghe also teaches reconstruction courses at the Institute of
Police Technology and Management (IPTM) at the University of Florida,
Jacksonville, Florida. He uses The Crash Zone, and PowerPoint animations
of crash scene diagrams both in his reconstruction work and training
classes.
Meyers points out that crash scene animations presented in court can
be real-time… to a degree. “I give my presentations in a
sequence, whereby the positions are time/distance accurate, but the sequence
itself may not be. But you can show the timing of each sequence up to
the moment that the crash occurred,” Meyers said. “As the
vehicles move in, you can change a displayed time value along with the
positions so that the sequence’s frames are time-distance accurate.”
Another benefit of animated sequences of a crash scene is that the animation
helps the audience actually see the entire crash event from start to
finish versus what normally is just a static diagram often supplemented
with too much technical detail from the presenter.
“If all you had was a static drawing created from the results of
the crash,” Meyers said, “it would be difficult to describe
the entire collision process. But when you can show it through animation,
you can show, for instance, how much time was left before drivers could
respond. You may be able to show how a collision was unavoidable,” Meyers
added. “Or, you can show how each movement of a vehicle is supported
by the physical evidence on the ground surface. You can lead the jurors
through a logical sequence so they can better understand how you (the
reconstructionist) believe this happened.” |