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.
SPECIAL COVERAGE: TCSO Reserve Deputy Shooting Controversy
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 to make 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.
In light of the report, protesters showed up outside the sheriff's office to voice their opinions Wednesday.
Protesters have been asking for the sheriff's resignation, and the report is new ammunition behind their request as the findings raised concerns about Bates' behavior in the field.
Eric Harris's brother, Andre, said he's known it.
"This is just the beginning of the unraveling of what's been going on for way too long," he said.
"Well, if Bates is not trained, who else is not trained," protester Stacy Kamau asked.
Sheriff Stanley Glanz mentioned the investigation in his media briefing Monday.
Glanz: "There was an investigation that occurred under sheriff Edwards."
Reporter: "What was the outcome of that?
Glanz: "I'm not sure. I believe that they found that there was no special treatment."
Brian Edwards, the undersheriff back in 2009, said he doesn't remember any investigation into Bates' behavior.
The sheriff's office said no action was taken on the investigation's findings.
Protest organizer Marq Lewis believes this is further proof of a cover-up by the sheriff.
"It's time for him to step down. No questions. He needs to step down," he said.
But the sheriff has made it clear that he has no plans to resign.
Andre Harris also acknowledges that his brother is one of several people who have died recently at the hands of law enforcement officers.
He said he's representing those who have been mistreated by those sworn to protect and serve.