Officer Frank Hernandez, 49, was seen April 27 on cellphone video recorded by a bystander, and later on his own body camera footage, repeatedly punching the 28-year-old trespassing suspect who had his hands behind his back.
The suspect did not appear to be physically resisting the officer, though he was exchanging heated words with him. The officer later claimed that the suspect had first grabbed and injured his hand. Both men's hands were not visible at the moment on camera.
"This is a disturbing case of the illegal use of force at the hands of a police officer," District Attorney Jackie Lacey said. "In this case, we believe the force was neither legally necessary nor reasonable."
Hernandez has been charged with one felony count of assault under color of authority. He is expected to be arraigned Thursday.
RELATED: Police bodycam video shows Boyle Heights confrontation
In the video after backup arrives, the officer is heard telling the suspect "you (expletive) grabbed my hand (expletive). That's why I hit you."
The suspect denies grabbing him and the officer continues to insist he grabbed him, showing him an injured finger.
The suspect was later released from custody.
A community member provided cellphone footage to a police supervisor at the scene. After reviewing the cellphone video and the officer's body camera footage, the supervisor notified his commanding officer and Internal Affairs was brought in to investigate.
In the video, it appears that Hernandez punched the suspect more than a dozen times on the head, neck and body. The suspect does not resist, but tries to protect himself.
The officer at that time was placed on home duty pending the investigation.
Bodycam video of the incident was released by LAPD.
The entire video released by the LAPD, including comments by Chief Michel Moore, can be seen here on YouTube.
Warning: contains strong language.
The LAPD on Tuesday released a statement referring to the video of the confrontation as "disturbing." the department said it has cooperated with the DA's office in the investigation and Hernandez "has been stripped of all police powers and has been assigned home."
Chief Moore said: "The Department has taken this matter very seriously from day one and he will be held accountable for his actions."