DALLAS (CBSDFW.COM) – The re-trial of a former Mesquite police officer who shot an unarmed man in the back is underway.

The first case ended with a mistrial nearly a year ago. Today there are more attorneys in the courtroom than before, but the testimony and evidence in the case against Derick Wiley is expected to be the same.

(credit: CBSDFW.COM)

Both the prosecution and defense have been there before. But this time when they walk away from the Dallas County Courthouse everyone is hoping a new jury will have reached a different outcome.

The case surrounds an encounter between Lyndo Jones, the unarmed man who was shot twice, and now fired Mesquite Officer Derick Wiley, the man who pulled the trigger.

As Wiley’s second trial got underway prosecutors showed the body cam video that detailed the entire parking lot ordeal. Wiley’s voice and hands are captured on the tape, showing his gun drawn and him loudly commanding Jones to get out of his truck and onto the ground. The video records Jones responding with “Yes sir.” and “Don’t shoot me.”

As Wiley has Jones on the ground, Jones asks, “What are you doing?” He frees himself from Wiley’s hold while on the ground, and attempts to run away. Wiley fires two shots.

Lyndo Jones

During testimony today the defense told jurors the case is not a simple one and boils down to something that took less than a minute to happen. “The miracle is in the detail and the analysis and having to break down 56 seconds of somebody’s life-threatening decision-making process,” said attorney Rafael Sierra.

Dallas County prosecutor Bryan Mitchell said everything jurors need to know is seen and backed up by the body cam video. “This is a case of a reckless police officer, who from the minute he showed up was hellbent on violence. He committed a crime… when you commit a crime you get prosecuted.”

The first witness called to the stand Monday was Lyndo Jones.

If convicted of aggravated assault by a public servant Wiley faces anywhere from 5 to 99 years in prison.