Federal prosecutors allege in an indictment unsealed Wednesday that three former New York prison guards beat an inmate bloody and one ripped dreadlocks from his head to use as a souvenir.

Authorities allege two guards and their sergeant violated the civil rights of Kevin Moore at Downstate Correctional Facility in Fishkill when he was being held Nov. 12, 2013 before transfer to New York City's Rikers Island for a court proceeding, then they covered up the beating.

They say Moore never physically threatened the officers and merely questioned why he was being placed in a mental-health unit overnight at the Hudson Valley prison.

"Excessive use of force in prisons, we believe, has reached crisis proportions in New York State," U.S. Attorney Preet Bharara told a news conference. His office also has been investigating the homicide of an inmate last year at nearby Fishkill Correctional Facility in a confrontation with guards.

Corrections Commissioner Anthony Annucci said the indictment "sends a strong message that we will pursue anyone that fails to uphold the integrity and professionalism that we place in our department."

The indictment says the Downstate guards - then-Sgt. Kathy Scott, George Santiago Jr. and Carson Morris - "brutally beat" Moore, giving him five fractured ribs, a collapsed lung and facial fractures.

"We allege that through retaliation, the charged corrections officers struck Moore with wooden batons, punched him repeatedly in the face and ribs, hit him in the head and the body and even ripped dreadlocks off his head, one allegedly picking up the dreadlocks from the floor, saying he wanted to save them as a trophy," Bharara said. "That beating left Moore in a pool of his own blood."

Moore was hospitalized 17 days. The indictment alleges Santiago took Moore's dreadlocks as a souvenir for his motorcycle. It also charges the three with falsifying records, saying the guards almost immediately concocted a story that Moore attacked a guard, bruising their colleague's back to support the lie.

Calls to their lawyers were not immediately returned Wednesday.

The indictment references two unindicted co-conspirators in the beating and cover-up.

State corrections officials said Scott and Santiago were fired. Morris was suspended for 10 months after arbitration, though corrections officials said they wanted him dismissed, and he no longer works there.

They also said the corrections department's investigations office has been overhauled, has "zero tolerance" for such behavior by officers and worked with federal and local prosecutors on this case.

The union representing New York's prison guards said it "in no way condoned" the alleged crimes by these three former members.

In a federal civil suit filed in June, Moore said the infirmary staff at the prison refused to treat his injuries, and he was instead locked overnight in solitary confinement, and his bloody clothes returned to him before he was taken to Rikers.

The lawsuit names the same three guards, two others and a registered nurse at the infirmary. It also names Annucci and Downstate Superintendent Ada Perez, alleging they knew of previous beatings and cover-ups, including what the suit alleged was Santiago's deliberate assault four months earlier on an inmate that broke the prisoner's ankle.