Accident investigation

A motor vehicle traffic accident occurs when a motor vehicle in motion on a public street causes death, injury, or property damage.

Accident investigation has defined as serving three general purposes:

1) to secure facts upon which to base an accident prevention program;

2) to determine whether or not laws have been violated, to gather evidence which will reveal the driver or pedestrian responsible for the accident and taking on-the-scene police action;

3) to ascertain the facts so that those involved in accidents can properly exercise claims under civil law.

The purpose of investigating accidents is to go back in reconstructing the accident as far аs possible from the position of final rest of the traffic unit involved and determine causations and circumstances leading to the accident situation.

From the facts presently known two questions arise: What are the causes that created the effect? and What are the circumstances that created the environment in which the event took place?

As is generally the rule in criminal investigation the investigator must reconstruct the accident from the questioning of witnesses and the examination of physical evidence found at the place where the accident occurred.

He must try to find a witness who can testify to the violation or some elements of it.

Key event. When two or more traffic units are involved in an accident, the conduct of each traffic unit is studied separately, as each traffic unit creates its own chain of events contributing to the total accident situation. In every accident one event in the chain of events is the " key event". This is the event that fixes the time and place of the accident. From this time and place the investigator can measure other events. The key event, therefore, determines the time, place and type of accident, and whichever of the following events occurs first:

l. Running of the road;

2. Collision on the road;

3. Over-turning or other non-collision event on the road.

Accident investigator. Accident investigators should have a standard procedure for handling accident investigations. Briefly, this routine is divided into six parts as follows:

1. Prepare for the investigation;

2. Prevent a secondary accident;

3. Secure the facts of the accident;

4. Record the facts;

5. Determine what happened;

6. Follow-up procedures.

Photographs should be taken as soon as possible after arrival at the scene.

Statements should be secured from the first officer on the scene аnd from witnesses and participants. If possible, have these individuals write their own stories of the accident.

Diagrams, together with photographs and statements, make up the portion of an investigation most likely to be utilised in court presentation of the case.

Skid marks must be identified with the vehicle that made them by a statement from the operator, statements of witnesses, by the investigator following each skid mark to the wheels of the vehicle or by a combination of these techniques. Measurements of skid marks should be made, if possible while the vehicle is still in its final rest position. This, plus photographs of the vehicle and skid marks, have a high evidential value in court presentations.