The video of Denver sheriff’s Deputy Edward Keller choking a noncombative inmate was recorded in the summer of 2011. But disciplinary and criminal investigations did not begin until more than two years later and only after the Denver jail inmate, Jamal Hunter, filed a federal lawsuit against Keller, another deputy and the city of Denver.

“At the time of his deposition on May 29, 2013, defendant Keller had not even been interviewed regarding the July 31, 2011 incident,” according to a brief by Hunter’s attorney, Qusair Mohamedbhai.

To this day, neither Keller nor anyone else has been punished in the incident in which Hunter was also tased twice — although a disciplinary panel has recommended Keller be suspended for 30 days.

The incident involving Keller happened only 13 days after another deputy, Gaynel Rumer, allegedly stood by while inmates beat Hunter and severely burned his genitals. Hunter claims he was pleading for better medical attention when Keller assaulted him.

The Hunter case led to the revelation that dozens of serious allegations against sheriff’s deputies by inmates had not been investigated.

VIDEO: See the video of Keller choking inmate Jamal Hunter.

Hunter’s treatment sparked a far-flung internal investigation of the Denver jail’s grievance practices. A judge has also recommended a federal investigation.

At the crossroads of local and federal allegations is a man who ran the Denver jail until his recent resignation after he became the target of an unrelated criminal investigation.

Former Denver Chief Michael Than, 46, once the No. 2 official at the Denver County Sheriff’s Department, was indicted April 25 by a Jefferson County grand jury on felony theft and tax-evasion charges. He was involved in deciding which of the deputies accused of serious offenses need to be investigated, officials say.

Video-surveillance footage shows Hunter approach Keller, who was at his desk in Pod-4D at 4:31 p.m. on July 31. Hunter appears to be saying something in an animated fashion. Hunter claims he asked Keller to see the nurse to care for his burns. Witnesses claim he was cursing and calling Keller racist. “You need to treat me better,” Hunter reportedly told Keller.

Hunter already had an appointment set up with a nurse, and Keller ordered the inmate, who was using abusive language, to return to his cell, Keller’s attorney, Josh Adam Marks of Boulder, said Friday. Marks said Keller was escorting Hunter into the cell when Hunter turned, faced Keller and took a step toward him.

“Mr. Hunter was an uncooperative inmate who refused to go back into his cell,” Marks said. “He took an aggressive step forward. The video and another deputy corroborate his side of the story.”

Keller is seen grabbing Hunter’s sleeve to escort him to his cell and then grabbing him with both hands on his neck and forcing him on the bunk. Three other deputies rush into the cell. A sergeant fires a stun gun at Hunter’s back from a foot away. Hunter is handcuffed.

“Mr. Keller, an officer for the Denver Sheriff Department, lost control of himself and attacked me, choking, punching and body slamming me without cause,” Hunter claimed in a grievance dated Aug. 10, 2011.

But Marks said that although force was used, “it was justified.”

Denver Independent Monitor Nicholas Mitchell was so stunned when he learned of the Hunter case that he ordered a review of 6,000 jail grievances.

“Mr. Hunter’s uninvestigated grievance alleging that he was choked and Tased prompted my evaluation of the entire Sheriff’s grievance process,” Mitchell said.

In December, Mitchell released the findings of a report that found 45 other serious complaints of deputy misconduct that had not been appropriately investigated and made recommendations for sweeping policy changes.

Mitchell’s report prompted the sheriff’s office to open investigations into complaints of sexual assault by deputies on inmates and numerous excessive force allegations.

On June 6, U.S. District Judge John Kane made an in-court petition to the U.S. Attorney’s office for a review of practices and policies of the Denver jail and sheriff’s offices after an allegation was made that two internal-affairs sergeants tried to intimidate Amos Page — a key witness in Hunter’s civil case — not to testify.

While Mitchell indicated Than’s role was important, he did not say the top administrator was the root of widescale lapses in investigating deputy misconduct.

“(Than) was intimately involved in looking at serious allegations of misconduct by deputies at the jail,” Mitchell said.

Than ran the downtown jail until his resignation Dec. 20. According to court records, he would stash TurboTax software from a Target store inside other merchandise, including a large dog food bag, a cooler and a padded packaging envelope.

“Chief Than oversaw the Denver City Jail during Mr. Hunter’s detention and approved many of the practices resulting in the constitutional harms to Mr. Hunter,” Mohamedbhai said.

But the problems at the jail were more widespread than the actions of one administrator, Mitchell said. He said 16 percent of all the misconduct grievances were filed against just four deputies in a force of 700 sheriff’s department employees.

Even though Denver jail policy required authorities to refer all allegations of criminal misconduct at the jail to internal-affairs officers, it was only being done on a per-case basis. A number of grievances had not been referred for investigation at all, Mitchell said.

“Denver’s practice of failing to investigate and discipline its sheriff’s deputies after serious allegations of misconduct against inmates created an environment that fostered the rampant use of excessive force that defendant Keller embodied when he brutalized Mr. Hunter,” Hunter’s lawsuit says.

Kirk Mitchell: 303-954-1206, kmitchell@denverpost.com or twitter.com/kirkmitchell