August 8, 2006

Special Feature:
Fatal car crashes - the science of collision investigation

Car crash on a major highway. Photo: Danny Bailey . Click image to enlarge

Story and photos by Jil McIntosh

On the popular television show CSI, investigators work in elegantly low-lit facilities, running tests through a dizzying array of sophisticated machines. Hollywood is seldom about reality, of course, and a visit to the Durham Regional Police's Collision Investigation Unit in Whitby, Ontario is nothing like the TV experience. Instead, it's a team of eight officers, toiling away in a neatly-kept, fluorescent-bathed basement office in this jurisdiction east of Toronto.

However, they do have something in common: like the actors on CSI, the Canadian investigators use a combination of high-tech equipment and old-fashioned police work, and they don't consider a case closed until all the questions are answered.

"If it's a single-vehicle collision, we investigate it the same way we would if seven vehicles were involved," says Detective Constable Dave Ashfield. "The families have a right to answers, and if we don't do this for every collision, we're not doing a service to the people. We put our heart and soul into every situation, so we can put people back on a forward path in their lives."

The Collision Investigation Unit works out of an office at the Durham Regional Police Headquarters in Whitby, Ontario. Click image to enlarge

The Collision Investigation Unit, or CIU, is a specialized team of officers that only investigates traffic collisions involving fatalities, serious or life-threatening injuries, or catastrophic property damage. The unit is on call 24 hours a day, seven days a week, and is dispatched when required after regular traffic officers respond to calls and determine the extent of damage. "If we hear air ambulance, or Sunnybrook or St. Mike's (Toronto hospitals specializing in trauma), we're out the door," Ashfield says. In 2005, the unit had 74 call-outs, 37 of them fatalities.

It takes specialized training to become a member of the CIU; officers advance through four levels, using classroom and on-the-job training. There is always at least one top level-four reconstructionist included when a team is called to a scene.

By the time the team arrives, the scene has usually been "locked down" or secured by the first police officers to arrive. "If it's catastrophic, we take over," Ashfield says. "We are in charge of the scene, over and above everybody. If somebody's been transported to the hospital, one of our guys goes there. We need to protect the evidence, such as if that person was impaired."

The CIU team follows a routine series of procedures, designed to collect as much evidence and information as possible. On television, investigators will often go back to the scene days later and find the crucial piece of evidence someone missed. In reality, factors such as weather, cleanup crews and the area's return to normal activity will usually move or destroy any remaining evidence. The team has only one opportunity to make sure they get everything right.

Sergeant John Givelas of the Traffic Services Branch, Collision Investigation Unit. Click image to enlarge

"One officer will go to the witnesses, and take statements," Ashfield says. "Another looks for road markings, the area of impact, gouges and scrapes on the road, parts from the cars. We put cones along where the cars went, to mark the path of the tires, and put down placards. Then a scenes-of-crime officer takes photographs.

"We stay at the scene as long as possible. Then we remove the vehicles, which become our property, because we will do a mechanical safety check on all vehicles if there's a fatality. Finally, we clean up the scene."

A major problem, Ashfield says, is eradication of evidence by well-meaning bystanders who don't realize the damage they're doing. He asks people to help anyone who's injured, but never to move any objects that don't need to be moved, and instead to direct traffic around them. "We had a case where everything matched up, except for one tire," he says. "We spent a couple of hours trying to figure out how the tire got into the ditch, because we use objects that came off the cars to determine crush factors. Then we found out that someone thought it was in the way of traffic, and they threw it there.

Detective Constable Dave Ashfield at his desk. The division uses sophisticated computer programs to reconstruct the collision. Click image to enlarge

"It's especially important when pedestrians are hit, because the impact often knocks them out of their shoes. People want to help and the first thing they usually do is grab the shoes and take them to the person. If they're left where they are, we can determine where the pedestrian was hit." Moving the shoes, Ashfield says, could prevent an officer from pinpointing the site of impact, which could mean that a motorist might get away with lesser charges.

The victims are the hardest part. On a previous visit to the CIU, I was shown photographs. Death by car crash isn't the sanitized version shown in the movies, with an artistic trickle of blood as the only sign of injury. Instead, brains are exposed, limbs are torn off, tongues loll out, facial features are unrecognizable. Perhaps drinking-and-driving warnings might have more effect if, instead of showing pictures of crashed cars, we could show pictures of crashed people.

It's hard on the officers. "You have to remember that it's your job, and you have to go with a professional approach," Ashfield says. "For the families involved, it's trauma and a lifestyle change. Someone may be gone, or someone may be in a wheelchair for the rest of their lives, and the family has to deal with it. You have to put all of that above your personal level. You have to be accountable, and go forward to that family. We don't just turn our backs. Some of our guys are dealing with families for years afterward."

The officers often wear T-shirts for their field work, since they can spend a lot of time crawling through ditches and into vehicles to collect evidence. Click image to enlarge

The CIU is responsible for informing families of the victims. A sergeant always goes, and is accompanied by another member of the team if possible. The CIU works closely with the force's Victims Services Unit, which offers help with emotional distress, as well as VCARS, the Victim Crisis Assistance and Referral Service, a not-for-profit volunteer group that works in conjunction with police, providing such services as emotional support and child care through difficult times. The notifying officers walk an emotional tightrope: they keep the family informed and answer questions as best they can, but they still must protect the rights of the accused, and can't always provide everything the family wants to know. Sometimes, despite the evidence, people simply won't believe that a collision happened the way it did. "There's nothing worse than getting up at 2 a.m., going to the scene, and then waking up a family to tell them," Ashfield says. "You know what you need to do, and you do it professionally. Sometimes, the investigation is the easiest part. What's hard is dealing with people whose lives have changed instantly because of this."

If charges are laid, the family will again become involved once the accused goes to court. "We have to go back to the family and bring them back into it," Ashfield says. "We have an up and down role. We try to help them get through it, then we take them back through it in court, and then we have to help them through it again. Our involvement never ends. You'll run into them in the grocery store, for example, and they'll remember you. You want to make a good first impression by handling the investigation properly."

Once all of the information is gathered and the families are notified, it's time for the officers to go back to the station and formulate the case. A full technical report is completed, no matter who is at fault. When autopsies are done, a CIU officer is always present for the driver, and usually for a passenger. Any necessary warrants are processed to obtain information from the car or its "black box" information centre, and the vehicles - which are kept in a secure police facility - are lined up to the angle of impact and photographed. Warrants may also be obtained for health records, to see if the driver might have had physical problems that contributed to the collision.

A computer program shows an animation of the collision, which the officers program using such evidence as tire marks, impact area and crush calculations. The program also includes animated vehicles superimposed on an actual aerial shot of the crash scene. Click image to enlarge

Numerous factors go into determining exactly what happened: the point of impact, where the cars ended up, damage on the vehicles, marks on the road, occupant injuries, where parts landed, weather conditions, objects hit. The officers use survey equipment, photographs, video and witness statements to try to piece everything together. One of the most useful tools is a computer program that uses the data to reproduce the collision from several angles: overhead, as a three-dimensional film, with animated cars superimposed over an actual aerial photograph of the scene, and even as the driver would have seen the collision through the windshield. These videos have been successfully admitted as evidence in several trials. "The windshield view can be very helpful," Ashfield says. "We can prove a driver should have been able to see a pedestrian, for example, even if he says the pedestrian wasn't visible."

Depending on the collision, police will prepare either an executive summary, or in the case of charges, a full reconstruction report which will be used in court. The vehicle remains with the police for viewing by the legal defence team, to ensure that it remains in its original condition, as allowed by law.

Surprisingly, fewer than 20 per cent of deaths in the Durham force's jurisdiction are alcohol-related, with only one so far in 2006 accountable to drinking and driving. "Aggressive driving and speeding were 27 per cent of last year's fatalities," Ashfield says. "A bigger factor we're noticing is what we call 'mature drivers', people over 55 years old. In six of the last seven years, the highest numbers were driver error by mature drivers that cost them or others their lives. The kids tend toward aggression and speeding, with peer pressure becoming an issue, but the over-55s are beyond that 'gotta get there yesterday' mentality.

"Most fatalities happen in the late afternoon or early evening, when the light makes it tougher to see, and people are fatigued. It's the end of the day, and they have lots of things on their mind. And we went through a phase with SUVs, because in poor weather, people think it'll get them there faster, but it won't stop them faster. Seven out of ten in the ditch are SUVs."

Ashfield brings up a video on his computer. A driver, alone in his car, drives too fast for road conditions and loses control around a curve. He crashes into a pole; the impact kills him instantly. The computer runs the scene over and over, in a split screen that shows a small square moving along the outline of a road, and above, superimposed on an aerial photograph of the curve. A timer counts off the seconds before and after the crash, until the car comes to a final stop. The video is the result of several hours' investigation at the scene, and later, many more hours of reconstruction at the unit's lab. So I ask, why bother? In a single-vehicle collision, with no third-party property damage and a driver who can't be charged, why go to so much trouble?

"If we don't do this for every collision, we're not doing a service to the people," Ashfield says. "We have to summarize what occurred. Perhaps there was a vehicle malfunction, or a driver injury, such as a heart attack or stroke. Families have a right to any answers we can give them. We have to ensure that each and every time, we've done the right thing, whether it's a single car, a pedestrian, or seven vehicles. I don't want to be asked the question I could have answered, if I'd only done my job right. We need to give families closure. We have to be accountable. That's our responsibility."

Jil McIntosh's automotive work and her garage includes cars both old and new; she writes for The Toronto Star Wheels, Old Autos, and Canadian Street Rodder.