Marco Topete, 39, was convicted of First Degree Murder with Special Circumstances after a high speed pursuit lead to the death of Yolo County Sheriff’s Deputy Jose Antonio Diaz on 15 June 2008. Diaz was fatally struck in the chest by one of seventeen .223 caliber rounds fired from an AR-15 Assault Rifle fired by Marco Topete.
The .223 Round pierced Diaz’ Kevlar vest and struck the Sherriff’s County vehicle which contained Topete’s daughter who was abandoned in Topete’s car when he fled on foot from the vehicle.
This Crime was one of the first to use 3d imaging ballistic trajectory tracking as a primary source of evidence used in court. I chose this case despite it being an American case because of its revolution in 3D Imaging and ballistics trajectory which sparked an interest and was briefly mentioned in my speak out.
Crime Scene and Evidence
The scene where the shooting took place was a house on the side of a road where Topete was run off the road. Topete proceeded to run around the house before firing on Diaz.
Fig.1 Seventeen .223 Remington cases and the bullet impact sights on the Sherriff’s County Vehicle.
Fig.2 Deputy Antonio Diaz’ Kevlar vest with location of fatal bullet entry.
Fig.3 Timing Data derived from Audio Frequency analysis of the crime recorded by Diaz’ dashboard camera.
Fig.4 Lecica ScanStation II scanning vehicle with trajectory rods.
An AR-15 Rifle similar to that used by Topete
Crime Scene photograph of Topete and Diaz’ cars.
Solving the crime
The crime scene’s largest chunks of evidence included the .223 Remington shells (fired from Topete’s AR-15 Rifle), Topete’s car, Diaz’s Sherriff’s County Vehicle w/ impact points, Topete’s daughter (still in Diaz’ cruiser), Diaz’s body w/ bullet entry and exit point, recording on Diaz’ dashboard camera and the AR-15 Assault Rifle found on Topete when he was arrested later that day.
Precision Simulations Inc. was tasked to use the physical evidence found at the crime scene to determine the shooters position at key moments during the event and to construct a 3D imaging with sufficient fidelity to the physical evidence found to have that animation submitted in trial.
The crime scene with the bullet trajectory paths was 3d imaged and through the method outlined in Fig.4. Once the Approximate position of the shooter was located, PSI then went on to analyze the position of Diaz when the fatal bullet struck him in the chest.
Upon analysis of the body and Kevlar vest it was determined that the round entered at 55 degrees left along horizontal axis and 45 degrees above along the vertical axis.
PSI created a 3D Model based upon Diaz’ measurements. This model was placed into the 3D rendered crime scene. Once lined up with the position of the bullet impact on the car and the shooter they determined the position of Diaz when the fatal 8th round struck him in the chest.
This revealed that Diaz reacted to the firing by crouching and turning 180 degrees in...