A prosecutor is calling for an investigation into allegations the reserve deputy accused of shooting a suspect dead instead of reaching for his Taser received preferential treatment when he was recruited. A memo from an internal police inquiry which surfaced earlier this week revealed colleagues expressed concerns about Robert Bates, 73, when he arrived at the Tulsa Sheriff's Office. Documents suggested the department also violated training policies when they employed Bates. He has been charged with second-degree manslaughter in relation to the death of Eric Harris during a botched sting on April 2. Scroll down for video . A memo has revealed that Robert Bates,73, who has been charged with second-degree manslaughter in the death of Eric Harris, was given special treatment when he was admitted into the Deputy program. He is pictured leaving his arraignment in in Tulsa, Oklahoma, on Tuesday . According to Tulsa World, District Attorney Steve Kunzweiler has begun contacting outside law enforcement agencies for further investigation after new information surfaced. He said on Friday: 'I am highly concerned about recent allegations that have surfaced and I have been in contact with independent law enforcement agencies regarding further investigation into these matters.' 'To protect the integrity of these investigations, I will not give details or comment further on any investigation that is underway,' he added. The memo concludes Bates didn't receive special treatment for admittance into the deputy program, but that he received special treatment once admitted. He was said to have used his personal car while on duty and made unauthorized vehicle stops. The inquiry came to the conclusion that high-ranking officers created an atmosphere where employees were intimidated about reporting violations of department policy. The report says it was prepared for former Undersheriff Brian Edwards, who says he doesn't remember its details. Dan Smolen, the attorney for Eric Harris, claimed that if the investigation's findings had been acted on in 2009 Harris might still be alive. He told CBS News: 'I think there are so many people who look on at so much corruption it's more than just a couple of people.' Sheriff's office spokesman Maj. Shannon Clark says he can't confirm the report but the department is preparing a statement. Bates appeared in Tulsa district court on Tuesday and pleaded not guilty to second-degree manslaughter in the death of Harris, who was killed during a botched sting. Charged: Bates (left in his mug shot) shot Harris (pictured right) and faces four years in prison if convicted . Sheriff Stanley Glanz said this week he believes that Bates received his required training. Bates, a Tulsa County volunteer, shot Harris, 44, after the man was confronted during an undercover gun-sale operation and ran past him. Video of the incident shows Bates chasing after Harris. In an attempt to subdue him, Bates went to grab his Taser, but was unaware he had actually pulled out his gun instead. In the disturbing clip, which was released by the sheriff's office, Bates can be heard shouting 'Taser! Taser!' When the gunshot goes off, he says: 'I shot him! I'm sorry.' The fatally-wounded father can be heard saying: 'Oh my god, he shot me! He shot me! He shot me, man' before adding: 'Oh, my god. I'm losing my breath!' Earlier this week the Harris family expressed their anger after learning that retired insurance executive Bates, who is out on $25,000 bond, would be allowed to take a month-long vacation to the Bahamas. A statement released by the family read: 'Whether intended or not, Mr. Bates' vacationing in the Bahamas at this time sends a message of apathy with respect to the shooting and Eric's life,' they said. This photo shows a deputy bending down to pick up Bates's dropped gun following the accidental shooting in Tulsa earlier this month. Harris is being held down on the ground, out of shot, by other deputies . Harris' son Aidan Fraley (pictured right with his uncle Andre Harris a week after his father's death), has said the police officers who allowed Bates to become a cop should be held accountable for his death . 'At a time when we are still mourning the death of a loved one that he shot down in the street, Mr. Bates will be relaxing and enjoying his wealth and privilege.' It is not clear when he is leaving for the holiday but Bates will next appear in court on July 2. He has previously visited the Bahamas with the sheriff, Stanley Glanz, and another reserve deputy and paid for part of Glanz's trip. In separate news conferences on Monday, the county sheriff and lawyers for Harris' family disagreed on whether the reserve officer should have been allowed to conduct police work. Sheriff Stanley Glanz said Bates, his long-time insurance agent and former campaign manager, had been properly trained and passed annual firearms certifications required by the state. Dan Smolen, the lawyer for Harris' family, said the Tulsa County Sheriff's Office violated a number of its internal policies by letting Bates carry his personal handgun after training with another weapon. Smolen also said the department failed to keep a permanent record of Bates' training, in violation of local policies. Records Bates released during the weekend showed that the volunteer officer was trained on a .45, not the weapon used in Harris' death. 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 before joining the Tulsa County force in 2008 and making a number of donations to the agency. He also was Glanz's campaign manager during the 2012 election.
Investigation shows colleagues expressed concerns about Robert Bates . Probe reveals he was not given special treatment during his application . However report in 2009 says he was once he was employed in Tulsa . Supervisors allegedly intimated colleagues to benefit Bates . He has been charged with second-degree manslaughter in relation to the death of Eric Harris in Tulsa, Oklahoma, on April 2 . District Attorney Steve Kunzweiler has begun contacting outside law enforcement agencies for further investigation .