The 73-year-old volunteer deputy who shot and killed Eric Harris after mistakenly drawing his gun instead of his Taser was charged with second-degree manslaughter on Monday, The New York Times reports.

The charge against Robert C. Bates—named the Tulsa County Sheriff’s Office “Deputy of the Year” just three years ago—was announced in a statement today by the Tulsa County District Attorney’s Office:

Mr. Bates is charged with Second-Degree Manslaughter involving culpable negligence. 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.”

At a press conference on Friday, police released footage of the deadly shooting, which an officer characterized as “an inadvertent mistake.” In the video, Bates can be heard shouting “Taser!” before a single gunshot rings out. “I shot him,” Bates then says, “I’m sorry.”

According to the Tulsa World, Bates is an insurance company executive who has donated thousands of dollars in equipment to the Sheriff’s Office since being made a reserve deputy in 2008, including “multiple vehicles, guns and stun guns.”

“There are lots of wealthy people in the reserve program,” a Sheriff’s Office spokesperson told the paper. “Many of them make donations of items. That’s not unusual at all.”

Tulsa police say Bates previously worked in law enforcement for one year, from 1964 to 1965.

[Image via Tulsa County Sheriff’s Office]