Robert Bates leaves a Tulsa County courtroom in 2015. He was denied bail while waiting on his sentencing hearing set for May 31. DYLAN GOFORTH/The Frontier

Robert Bates, a former Tulsa County Reserve deputy, could be released from prison as early as Thursday after serving less than half of his four-year sentence for second-degree manslaughter.

Records originally showed Bates was scheduled to be released as early as Oct. 13, though that date was later changed to Oct. 23, according to the Oklahoma Department of Corrections website. Bates, who had been sentenced to prison for four years, was eligible to earn credits toward early release.

Matt Elliott, spokesman for DOC, said on Wednesday that Bates had not yet been released, but that Bates’ last known “probable release date” was set for Oct. 19, though he noted release dates are “handled at the facility level.” A spokeswoman at North Fork Correctional Center, where Bates has been located since March, said the facility would not discuss prisoner release dates with the media.

Bates was charged in 2015 after killing Eric Harris during a botched undercover drug sting in north Tulsa. An undercover deputy on the Tulsa County Sheriff’s Office’s drug task force was attempting to buy an illegal firearm from Harris when Harris noticed other undercover officers closing in and fled.

Two deputies tackled Harris not long after, and Bates — 73 years old at the time and a volunteer on the task force — arrived and shot the subdued Harris once under the right arm, killing him.

Bates told investigators four days after the shooting that he had intended to use his Taser on Harris, and video recording by a surveillance camera purchased by Bates for the task force recording him announcing “Taser! Taser!” as he arrived on the scene.

Former Reserve Deputy Robert Bates

Bates went on trial about a year after the shooting, and was convicted after a six-day trial in which his defense argued that the shooting was not only excusable, it was not the cause of Harris’ death. Bates’ attorney Clark Brewster said in the trial that a medical expert’s report showed that Harris died of a drug-induced heart attack, rather than the bullet that pierced him under his right arm pit.

The four-year sentence recommended by Bates’ jury and upheld by a judge was the maximum allowable punishment in Oklahoma for second-degree manslaughter. It also made Bates one of only a handful of law enforcers around the nation convicted for a fatal on-duty shooting.

Second-degree manslaughter is not one of Oklahoma’s “85 percent statutes,” crimes in which a convicted person must serve 85 percent of the sentence before even being considered for probation or parole. Bates was one of thousands of inmates across who was able to earn credits during his incarceration in order to speed up his release.

The shooting touched off a chain of events that led to a grand jury indictment of former Sheriff Stanley Glanz.

Despite remorse, health concerns, Robert Bates sentenced to prison

One of the counts involved Glanz’s refusal to turn over a 2009 investigative report on favorable treatment given to Bates by TCSO. The report also found supervisors who expressed concerns about Bates’ lack of training were intimidated by top TCSO officials. Glanz eventually pleaded guilty and no contest to misdemeanor counts and resigned from office.

Bates had served as chair to somel of Glanz’s re-election campaigns, and had donated thousands of dollars to the former sheriff as he repeatedly ran for re-election. Bates also bought thousands of dollars worth of equipment for both the sheriff’s office and as gifts for some of TCSO’s higher-ups, many of whom were ousted in the fallout over the shooting.

Weeks after Harris was killed, The Frontier obtained an Internal Affairs report written years prior which detailed complaints against Bates, including that he often threatened to use his close relationship with Glanz against anyone who attempted to get in his way. The sheriff’s office was never able to turn over documentation proving that Bates had completed the hundreds of hours necessary to patrol on his own as a reserve deputy, and some members of TCSO complained in the IA report that they were forced to sign off on training they knew Bates had never completed.

The whole saga not only ended in the removal of Glanz, it resulted in an upheaval of the entire reserve deputy program, one that now has only a handful of members compared to the more than 100 it had at any given time during Glanz’s tenure.

During Bates’ sentencing hearing in May 2016, Brewster argued that prison might kill the aging former insurance executive.