Officer Amy Wilburn shot Kelvion Walker in 2013 at the end of a car chase.
The incident was recorded by a dash camera.
Officer Wilburn was fired and charged with aggravated assault, and Walker survived and sued her.
His attorney, Geoff Henley, requested the gun as evidence, but instead of keeping it locked up, the Dallas Police Department issued it to at least two other officers.
The gun has now been returned to the property room.
Henley says he hopes it was not tampered with or damaged.