TULSA, Okla. -- A former Oklahoma volunteer sheriff's deputy who said he mistook his handgun for his stun gun when he fatally shot an unarmed suspect last year was convicted of second-degree manslaughter on Wednesday.
Jurors handed down the verdict in the case of 74-year-old Robert Bates, a wealthy insurance executive accused of fatally shooting Eric Harris while working with Tulsa County sheriff's deputies last year during an illegal gun sales sting. Harris, who had run from deputies, was restrained and unarmed when he was shot.
The shooting -- which was caught on video -- sparked several investigations that, among other things, revealed an internal 2009 memo questioning Bates' qualifications as a volunteer deputy and showed that Bates, a close friend of the sheriff's, had donated thousands of dollars in cash, vehicles and equipment to the agency.
Bates faces up to four years in prison.
Bates' defense attorneys argued at trial that methamphetamine found in Harris' system, along with his cardiac health, caused his death. Defense attorneys called the killing an "excusable homicide."
CBS affiliate KOTV reports that defense attorney Clark Brewster said Harris made choices that resulted in his own death and that Bates acted reasonably and was "someone we should be proud of."
But prosecutors told jurors that Bates was guilty of culpable negligence when he shot Harris. One deputy testified that Bates apparently dozed off minutes before Harris fled from deputies.
Following the shooting, an outside consultant hired to review the sheriff's office determined that it suffered from a "system-wide failure of leadership and supervision" and had been in a "perceptible decline" for more than a decade. The reserve deputy program was later suspended.
Weeks after Harris was killed, an internal sheriff's office memo from 2009 was released by an attorney for Harris' family that alleged superiors knew Bates didn't have enough training but pressured others to look the other way because of his relationship with the sheriff and the agency.
A grand jury also investigated the agency and indicted the longtime sheriff, Stanley Glanz, in September, accusing him of failing to release the 2009 memo. He resigned on Nov. 1.
The new sheriff, who was sworn into office earlier this month, has detailed plans to reform and revive the reserve deputy program.
Bates, who sold his insurance business for $6 million in 1999, was trained to be a Tulsa Police Department patrolman in 1964 but left in 1965. He was out of law enforcement for 35 years, returning for volunteer work in Florida in 2000-01 -- doing ride-alongs -- before joining the Tulsa County force in 2008 and making a number of donations to the agency.