​Deputy who fired gun instead of taser was investigated in 2009

Robert Bates' behavior in the field was quest... 01:57

TULSA, Okla. -- CBS News has learned that a 2009 investigation by the Tulsa Sheriff's Office concluded that there were concerns over Robert Bates behavior in the field. Bates, a 73-year-old reserve deputy, pleaded not guilty to second-degree manslaughter charges in the death of Eric Harris. Bates says he shot and killed Harris by mistake after pulling his gun instead of his taser.

Since the incident there have been allegations that Bates was not properly trained. CBS News learned that in 2009, the Tulsa Sheriff's Office launched an internal investigation to find out if Bates received special treatment during training and while working as a reserve deputy. They also investigated whether supervisors pressured training officers on Bates' behalf.

Robert Bates, left, is accused in the fatal shooting of Eric Harris CBS News

The investigation concluded Bates' training was questionable and that he was given preferential treatment.

The investigation found that deputies voiced concerns about Bates' behavior in the field, almost from the very beginning. Bates reportedly used his personal car while on duty and made unauthorized vehicle stops. When confronted Bates said that he could do what he wanted, and that anyone who had a problem with him should go see the sheriff.

The investigation concluded that high ranking officers created an atmosphere where employees were intimidated in order to violate department policy.

Dan Smolen, the attorney for Eric Harris, says if the findings had been acted on in 2009 Harris might still be alive.

"I think there are so many people who look on at so much corruption it's more than just a couple of people," said Smolen.

A spokesman for the Tulsa Sheriff acknowledged that some type of internal review was conducted, but that there was no further action taken. Sheriff Stanley Glanz said this week he believes Bates received his required training.