Ballistics

In Officer-Involved Shooting events, the trajectory of bulletÍs fired and their ejected casings are critical pieces of the evidentiary puzzle. Although considerable effort is expended in documenting this evidence at the scene, it becomes a challenge to effectively utilize the data to form solid, defensible conclusions about crucial legal issues such as the reasonableness of the force used.

PSI uses Two types of Working Models to assist the expert and attorney determining: (1)Who was standing where, (2)Who fired Which Rounds and (3) What position was Target in when each Round was Fired?

• Bipedal Trajectory Model
• Physical Evidence Mapping

Bipedal Trajectory Model

In order to determine the body position of a human at the time the bullet struck, PSI develops a 3D working model of the human form and all of the entry and exit wounds from the bullets that struck.

This model can be moved and manipulated until the specific bullet trajectory lines up with the known position of the shooter

The resulting body position of the 3D model approximates the position the shooting subject was in when the specific bullet struck

Physical Evidence Mapping

At the crime scene, investigators measure the position of each bullet hole and shell casing that can be located. This information is contained in their reports and can be very useful in helping experts determine what happened and what actions were performed by each participant. What is needed to make the most effective use of this data is a comprehensive map of the physical evidence. By mapping the locations of the bullet holes and ejected casings, over a scale 3D model of the event scene, PSI provides a powerful tool to determine (1)Who was standing where and(2) Who fired which rounds. The resulting 3D model allows expert to analyze the scene, as if they were there, in the lab, with all the powerful measuring tools available on the computer and without the time constraints and confusion of the crime scene itself.