A Pasco County deputy was arrested on a charge of child abuse Friday, accused of choking and threatening a 16-year-old jail inmate.

Deputy Norman Grant had been on administrative leave while the June 20 incident was investigated. He was fired Friday. He had worked at the Sheriff's Office since April 2006.

According to Pasco sheriff's officials, the teenage inmate, whose name was not released, was banging his head against his cell door around 5:30 p.m. Deputies put him in a restraint chair with leg straps and handcuffed him. After he was able to loosen the straps, Grant tightened them.

The inmate complained that the straps were too tight and pushed his legs out to stop Grant from tightening them further. Grant, who is about 6 feet tall and weighs 300 pounds, grabbed the boy's neck with his left hand and choked him to the point where he could not breathe, according to an arrest report.

Grant then whispered, "Stop or I'll break your neck," according to the report.

About 20 minutes later, the inmate told a mental health counselor that he had been choked, and the counselor noticed red marks on the boy's neck and a scrape on his chin.

The incident was captured on video, but the Sheriff's Office declined to release it because it's evidence in the case.

This isn't the first time Grant, 44, has been under the Sheriff's Office microscope. He was the subject of three previous internal investigations.

In 2011, according to Sheriff's Office records, he pepper sprayed an inmate who was repeatedly pressing an emergency call button and verbally threatening another inmate. The inmate was secured in his cell, and the pepper spray can malfunctioned. Grant said the rules didn't specify that he couldn't pepper spray an inmate in his cell.

In 2012, he was investigated after he punched a handcuffed and shackled inmate in the head several times. Other deputies were present for the incident, but the details of their reports conflicted.

That inmate sued, and in February, Grant was investigated again after the inmate told deputies that Grant threatened harm to him and his family if he continued with the lawsuit. The inmate said Grant also warned a trainee who was with him to keep quiet about the confrontation.

Pasco Sheriff Chris Nocco said Friday that a lack of evidence cleared Grant in all three investigations.

He called the alleged incidents "dots along the way" to the child abuse charge.

"This deputy probably should've never worn a badge," he said.

But in January 2012, Grant was awarded the Pasco Sheriff's Office Meritorious Service Medal for Courage after he was injured while restraining a violent inmate.

Grant was booked into the jail at 7:45 a.m. Friday and released after posting $5,000 bail.

Clare Lennon can be reached at clennon@tampabay.com.