INTEGRITY: Raw Data Files vs. Artistic License

By James A. “Jim” Moore,
PSFM Secretary (Dallas Police Department – Retired)

Do you recall the television show Dragnet, starring Jack Webb as a tough LAPD Detective. Well, Jack when talking with a witness, would always say, “just state the facts,” so here are the basic facts:

Several years ago, my office became involved in the reconstruction of a multiple vehicle collision that occurred on a highly trafficked, 10-lane, Jersey barrier divided, section of an Interstate Highway with inside and outside shoulders.

The pre-collision scenario of the case involved a male motorist stopping on the 10-foot wide inside shoulder of the roadway to assist a female motorist with a flat tire on the back right of her vehicle. The gentleman was in the process of putting the spare tire on the vehicle when a marked police vehicle stopped rearward of stopped vehicles. The officer’s vehicle, according to witnesses was either half way or three quarters of the way into the inside 12-foot wide lane of travel with its overhead emergency lights on. The officer remained seated in his vehicle and the vehicle was within 600 feet from the crest of a hill, rearward of his location. The speed limit in the area is posted at 60 MPH. Approximately ten minutes later, the driver of a large SUV traveling behind a semi-truck in the second lane, on approach to the crest of the hill, noticed that the truck and traffic in the inside lane were slowing and then, after cresting the hill, the SUV driver changed lanes into the inside lane of travel to pass the truck.

The collision scenario involved the SUV making front left contact to the back right of the police vehicle. The police vehicle, displaced forward left two rear tire marks on the pavement and then made front to rear contact with the female motorist’s vehicle. As a result of this contact, the female motorist’s vehicle was displaced forward making front to rear contact with the male motorist’s vehicle. During this phase of the collision scenario, the female and the male were standing between their respective vehicles and the Jersey barrier and both motorists-pedestrians received injuries as a result of this collision.

Since this was a major accident with serious injuries and involved a police vehicle, a team of Accident Investigators were subsequently on-scene to investigate and reconstruct the collision. During the on-scene investigation, the crash site and immediate area were forensically documented.

As in most civil matters, my involvement came several days after the crash. Upon receipt of the case assignment from the SUV’s insurance company, the scene was inspected, photographed and forensically documented, including the investigating officer(s) paint markings. An Open Records Request was submitted and knowing the scene was forensically mapped, a request was specifically made for their ‘raw data’ file(s), a copy of the initial .dxf file(s) and a color copy of the completed CAD diagram. The police agency, in response to the request, only provided an 8½ x 11½ black and white diagram.

Now, as Mr. Paul Harvey would say, here is the rest of the story.

Initially, members of my team noted a discrepancy between the police diagram and our forensic diagram. It was obvious that the location of the two rear tire marks left by the skidding police vehicle on the police diagram differed from our work. The police diagram depicted the tire marks several feet closer to the yellow inside fog line than our diagram did.

During our scene investigation, numerous photographs were taken of the tire marks and included photographs of the each end of the tire marks with an elevation rod perpendicular to the fog line, to give some lateral relationship between the tire marks and the fog line. The photographs also well documented the investigating officer(s) orange paint marks, denoting the beginning and end of the tire marks. The police ‘at-scene’ photographs were then compared to our ‘post-collision’ photographs and the location of the tire marks were similar.

A second Open Records Request was submitted, specifically requesting the raw data file(s) and the initial .dxf file(s), including the name and phone number of the officer responsible for maintaining the files.

After receiving the raw data and .dxf files, the information was compared to our forensic documentation and diagram and they matched within 1-inch +/-. It was also noted that each tire mark was documented using a line code with one ‘shot’ at the beginning and one shot at the end of each mark. Using their .dxf file, it was determine that the tire marks and one of the four nodes were moved laterally left in their final CAD diagram, placing most of the police vehicle off the roadway at the time of the collision.

Personal contact was made with the officer who downloaded the data recorder, created the initial .dxf file and subsequent CAD diagram (not the investigating officer) regarding the discrepancy, and he saw no reason to review and/or revise the police diagram.

The insurance company, based upon our findings and analysis, subsequently filed a law suit against the police department and this entire episode, with multiple diagrams and overlays, was discussed in trial, before a Judge, Jury Panel, three Attorneys, spectators and court room personnel. The testifying officer (not the investigating officer) when confronted with the documentation did tell the truth, stating that the investigating officer told him that the tire marks did not look right and to move them a little to the left. Immediately following his testimony, the Judge called for recess and called the Attorneys and testifying officer into his chambers. After the recess, the Judge announced that the case had been settled (favorably for the Plaintiff/insurance company) and thanked the Jury Panel for their participation.


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