NEW YORK » A Rikers Island jail guard kicked an inmate to death in 2012 and then conspired with two others to lie about what happened, a federal prosecutor said Wednesday in announcing two arrests and a guilty plea and what he called "more sad news" out of the nation’s second-largest jail system.

U.S. Attorney Preet Bharara announced the arrests of former guard Brian Coll and current guard Byron Taylor in Ronald Spear’s death following a federal investigation that began when state authorities decided not to bring charges.

"Rikers inmates, although walled off from the rest of society, are not walled off from the protections of our Constitution," Preet said at a news conference.

The prosecutor described "more sad news out of Rikers Island" six months after suing New York City to address what a Justice Department investigation found was a "deep-seated culture of violence" toward inmates there, particularly the young.

The Spear investigation showed that guards worked together to thwart investigators probing how the 52-year-old inmate awaiting trial on a burglary charge was killed Dec. 19, 2012, according to a criminal complaint in Manhattan federal court.

Spear was held face-down on the jail floor in view of fellow inmates shouting, "They’re kicking him!" and "They’re killing him!" according to the criminal complaint written by FBI Agent Vanessa M. Tibbits.

She said witnesses described Coll repeatedly kicking Spear before kneeling next to him, lifting his head and saying, "Remember that I’m the one who did this to you," before dropping his head on the hard floor.

The FBI agent said a corrections captain told investigators that Coll asked six to eight months after Spear died whether he should get a teardrop tattoo on his eyelid, something street gang members do after they kill someone. She said Coll told the captain "I beat the case" after the state court case ended without charges.

The complaint said two guards were cooperating, including former corrections officer Anthony Torres, 49, of New Rochelle, who has pleaded guilty to conspiring to commit obstruction of justice and filing a false report.

Coll, 45, of Smithtown, was charged with depriving Spear of his rights, obstruction of justice, filing a false report and conspiracy. Taylor, 31, of Brentwood, faces conspiracy and obstruction of justice charges. Authorities said Taylor helped restrain Spear and then lied about his role.

Prosecutor Brooke E. Cucinella said the obstruction charge carries a potential prison term of 20 years. Upon conviction, sentencing guidelines call for more than 10 years to be spent in prison, he said.

New York City settled a lawsuit last year for $2.75 million stemming from the death. Lawyers say Spear complained that guards retaliated against him for contacting lawyers about his kidney disease treatment.

Attorney Samuel Braverman said lawyers "will defend Mr. Taylor vigorously and cross each bridge as we get to it." Taylor was released on $200,000 bail.

Sam Schmidt, Coll’s attorney, told a magistrate judge before his client’s bail was set at $500,000 that Coll has been undergoing treatment for psychiatric issues since Spear died, is estranged from most of his family, is separated from his wife and children and has depleted his assets. Schmidt confirmed that Coll’s father has an order of protection against him.

Coll is expected to make bail and be released from custody Thursday. He was banned from possessing any dangerous weapons, using alcohol excessively and was ordered to stay away from any potential fact witnesses in the case. He also must undergo mental health and substance abuse treatment.

Outside court, Schmidt declined comment. A lawyer for Torres declined to comment.

Zoe Salzman, a Spear family attorney, said the family was grateful for the federal prosecution.

New York’s 11,000 daily inmate jail system fell under increased scrutiny over the past year after two seriously mentally ill inmates at Rikers Island died and other problems.