The incident occurred in June in Diamond Bar. L.A. County Sheriff's Deputies arrived at the scene after a number of residents called 911, saying they saw the man and heard him firing shots.
"There's a person with an assault rifle and a bullet proof vest walking down Crooked Creek Drive... I just heard another gunshot down the street," one caller was recorded saying to emergency services.
Thirty-year-old Benjamin Chin stabbed his mother in the back during an altercation mother. She later begged the deputies not to shoot Chin as she bled from her injuries.
"Please don't shoot my son!" she can be heard saying to deputies in newly released bodycam video.
Bodycam video then shows deputies track down Chin, who was approaching a driver stopped on Diamond Bar Boulevard.
Deputies repeatedly ordered Chin to drop the gun, but he did not comply and that was when deputies fired.
Chin was rushed to the hospital but later died from his injuries.
Detectives recovered an AR-15 that was partially digitally printed, making it untraceable ghost gun.
Chin's mother recovered from her stab wounds and the deadly use of force incident is under investigation by the sheriff's department' Internal Affairs Bureau.
The incident will be presented to the District Attorney's office for review as well.