AFRO Sunday33-001

Tulsa County reserve deputy, 73-year-old Robert Bates (left) , thought he was holding a stun gun, not his handgun, when he fatally shot 44-year-old Eric Harris (right). (AP Photos)

TULSA, Okla. (AP) — Prosecutors charged a reserve sheriff’s deputy with manslaughter Monday in the death of a man who was fatally shot as he lay on the ground at the officer’s feet.

Tulsa County prosecutors filed a second-degree manslaughter charge against 73-year-old Robert Bates.

A police investigator has said Bates, who is white, thought he drew a stun gun, not his handgun, when he fired at 44-year-old Eric Harris, who was black, in the April 2 incident.

Bates is charged with second-degree manslaughter “involving culpable negligence,” Tulsa County District Attorney Steve Kunzweiler said in a statement.

Killings by Police Oklahoma

In this Friday, April 10, 2015, photo, a Taser and handgun, similar to the weapons in possession of Tulsa County reserve deputy Robert Bates during a pursuit of Eric Harris, are displayed in Tulsa, Okla. Police say Bates thought he was holding a Taser, not his handgun, when he fatally shot Harris during an arrest that was caught on video in Tulsa. (Cory Young/Tulsa World via AP)

Oklahoma law defines culpable negligence as “the omission to do something which a reasonably careful person would do, or the lack of the usual ordinary care and caution in the performance of an act usually and ordinarily exercised by a person under similar circumstances and conditions,” Kunzweiler said.

A video of the incident shot by deputies with sunglass cameras and released Friday at the request of the victim’s family, shows a deputy chase and tackle Harris, whom they said tried to sell an illegal gun to an undercover officer.

As the deputy subdues Harris on the ground, a gunshot rings out and a man says: “Oh, I shot him. I’m sorry.”

Harris was treated by medics at the scene and died in a Tulsa hospital.

A telephone message left Monday with Bates’ attorney, Scott Woods, was not immediately returned.