A St. Louis man may have been trying to defend himself when he was shot and killed by a former police officer.

That was just one part of the sworn testimony that came out Wednesday during the high-profile murder trial of Jason Stockley.

Stockley, an ex-cop with the St. Louis Police Department, is charged with first-degree murder and armed criminal action for the December 2011 shooting death of Anthony Lamar Smith, 24.

The deadly encounter unfolded near Acme & W. Florissant in north city following a suspected drug deal involving Smith and a high-speed chase and crash.

Dr. Gershom Norfleet, a forensic pathologist who conducted Smith’s autopsy, testified Smith was shot a total five times in his left side while inside a car, but that two shots proved to be fatal.

Norfleet said one of those deadly shots was “straight through” Smith’s heart.

He also testified that the “through and through” gunshot in Smith’s left forearm “could be interpreted” as a “defensive wound” as Stockley fired from outside the driver’s side window of Smith’s car.

Stockley’s defense team believes Smith was leaning to the right during the gunfire in an effort to reach for a firearm on the passenger’s front seat.

Norfleet said there could be “multiple scenarios” based on Smith’s positioning in the vehicle and the trajectory of the gunshot wounds to his body.

Marijuana was also in Smith’s system at the time of his death, according to autopsy records presented in court.

Testimony on the second day of the trial also focused on the gun found in Smith’s car and Stockley’s behavior on scene.

Prosecutors contend that only Stockley’s DNA was discovered on the 38 mm, including a presumptive crime lab test that showed blood on a screw head located inside the firearm’s grip.

Stockley’s defense team argues it was rust, not blood, on the screw and that no confirmatory testing was completed to ensure the most accurate results.

Prosecutors believe Stockley planted the weapon inside Smith’s car to try and cover up his alleged crime.

St. Louis Police Officer Elijah Simpson, who testified earlier in the day, said he saw no gun inside Smith’s car upon his arrival at the shooting scene.

Simpson said of 10 officers on scene, including himself, no one attempted to render aid to Smith, even though “he appeared alive.”

Simpson said he thought it was “strange” Stockley continued to be allowed to travel back and forth between Smith’s car and his department SUV, adding the SUV was not searched.

Simpson testified Stockley was the only officer who took his gloves off, as other officers were putting them on to avoid contaminating evidence potentially.

The department had no policy in 2011 barring Stockley from having access to Smith’s car or the gun inside even though he had just been involved in an officer-involved shooting, defense attorneys argued.

Stockley’s attorneys also said suspects “choose” the circumstances that determine their fate, leaving officers to make split-second decisions.

The state has five more witnesses to call. The trial is expected to last into next week.