A Florida prisoner who claims a deputy beat him into submission at Orleans Parish Prison has filed a federal lawsuit against Sheriff Marlin Gusman, adding to the avalanche of litigation surrounding the troubled jail.

Darran Reppond, a convicted killer who was being housed briefly at OPP to testify in a local death-penalty case, claims the Sheriff’s Office conducted a short-circuited investigation of the December 2013 incident and fostered a “practice of refusing to hold staff members accountable for unjustified guard-on-inmate physical abuse.”

Gusman’s investigators have blamed Reppond for instigating the jailhouse run-in, determining that Deputy Erick Smith manhandled Reppond after the inmate “chest-bumped” him and refused to return to his cell, according to Sheriff’s Office records.

The Sheriff’s Office cleared Smith of wrongdoing, deeming the force he used to be a proportional response.

Reppond’s lawsuit, filed in U.S. District Court by New Orleans attorney John Adcock, claims the internal probe was sorely lacking and that Smith threatened inmate witnesses “not to say anything” about the incident.

The lawsuit places the alleged assault in the context of previous violence at the jail and the unconstitutional conditions that led to a 2013 federal consent decree on improving jail conditions that was reached by Gusman and the U.S. Justice Department. It claims the Sheriff’s Office violated Reppond’s Eighth Amendment protection from “cruel and unusual punishment.”

“The assault lasted about seven to 10 minutes before three officers pulled Smith off of Mr. Reppond,” the lawsuit claims. “At one point, Mr. Reppond stood with his back against the wall with his arms spread across the surface to show the deputy that he was non-combative.”

Reppond and Smith have offered sharply conflicting accounts of their confrontation, which happened Dec. 1, 2013, as Smith was attempting to “lock down” a cellblock in the jail’s Templeman V facility. As a witness in a pending trial, Reppond was supposed to be held in protective custody, but he apparently was being housed among the mentally ill inmates due to a space issue.

Reppond had been called to testify in Criminal District Court on behalf of Rogers LaCaze, a condemned prisoner who claims he is innocent of the 1995 massacre at the Kim Anh restaurant in New Orleans East.

Reppond maintains he previously had shared a cell with a man who confessed to killing a police officer and two young siblings at the restaurant in a robbery gone awry — the crime that sent LaCaze to death row. LaCaze, who claims he was at a pool hall at the time of the killings, has asked a judge to grant him a new trial, arguing, among other things, that prosecutors withheld eyewitness statements.

Reppond’s run-in with Smith happened while the inmate was demanding to make a phone call from OPP. According to Smith’s report, Reppond became belligerent when he was told to return to his cell and said he “had nothing to lose,” as he already was serving a life sentence.

Reppond, who has a criminal history in several states, threatened the deputy and uttered a racial slur, according to one inmate’s statement. But Sheriff’s Office records show deputies also sought to de-escalate the situation by telling Smith to back away and leave the tier.

“Inmate Reppond began to get more violent and braced up to me as if he was going to strike me,” Smith wrote in his report, “and that’s when I took hold of his uniform and walked him to his cell. Once in his cell, I let inmate Reppond go and told him not to get up.”

In his lawsuit, Reppond says that Smith slammed him into the floor, stuck his knee in his back and dragged him down the tier.

“Smith threw Mr. Reppond into his cell — into the small space between the toilet and the bed rack of the cell — and proceeded to ‘vigorously choke’ Mr. Reppond while hitting him against the rack,” the lawsuit says. “When he threw Mr. Reppond into the cell, Mr. Reppond’s left ankle hit the side of the cell door, causing a large and painful injury to his left ankle.”

Detectives tried to interview several inmates on the tier, “but none of the other inmates wished to cooperate with the investigation, stating they either did not wish to make an official statement or they did not witness the incident,” according to a Sheriff’s Office memorandum.

Sheriff’s Office records say Reppond received medical treatment for “minor scratches to the right side of his chest and an abrasion to the left ankle.” The lawsuit, however, claims Reppond “was not provided anything other than one Band-Aid and two Tylenol.”

OPP has long been notorious for its inmate-on-inmate violence, which formed the foundation for the consent decree, a sweeping, court-ordered plan for reforms. But the jail also has seen cases involving deputies accused of striking inmates, among other misconduct.

The Sheriff’s Office confirmed earlier this month that Deputy James Henry is being investigated for allegedly “rebuffing” a juvenile inmate with a blow to the face in the jail’s Conchetta facility.

Follow Jim Mustian on Twitter, @JimMustian.