The Southern Center for Human Rights on Wednesday filed a federal lawsuit accusing the state of negligence in the murder of Damion MacClain.

MacClain was an inmate at Hays State Prison, a high-security facility in northwest Georgia. The lawsuit, filed on behalf of his mother, accuses the state of knowing for years that security at Hays had deteriorated to “unconstitutional levels” where cell door locks didn’t work or were easily defeated, allowing some of Georgia’s most violent prisoners to roam free at night.

RaHonda MacClain had previously told prison officials her son had been threatened by other inmates and was in danger, the center said.

MacClain was the second of three men murdered at Hays in a five-week period from December 2012 to February 2013. A state audit in September 2012 found that 184 locks failed out of 442 locks inspected at Hays. Other state prisons also struggle with locks, the AJC found in a review of audits at each of the state’s highest-security prisons.

“I want those responsible for the death of my only son, Damion, to be held accountable,” RaHonda MacClain said in a statement to The Atlanta Journal-Constitution. “No parent should have to bury her child under circumstances like this.”

Efforts to reach officials with the Department of Corrections were unsuccessful late Wednesday. A spokeswoman for Attorney General Sam Olens, who will likely defend the state in the lawsuit, said she had not seen the suit and could not comment.

The civil rights lawsuit claims MacClain was beaten and strangled to death by other inmates on Dec. 26. Broken door locks “long ignored by defendants” allowed the inmates to leave their cells to kill MacClain. The suit seeks compensatory and punitive damages.

The AJC reported in July that state officials had signed an emergency order for $1 million in security upgrades at Hays and Department of Corrections officials acknowledged that locks have been a concern for several years.

Hays, which can house almost 1,700 violent men, has been one of the most dangerous prisons in the state system for years. Inmates use contraband cellphones to coordinate gang activity and other criminal enterprises, an AJC investigation found. The Southern Center for Human Rights has also alleged that Hays administrators would alert inmates of upcoming searches, or shakedowns, so the prison would shine in departmental security audits.

Corrections Department audits for 2008-2012 showed that some of the facility’s cell door locks could be easily opened.

“Mr. MacClain’s death was both foreseeable and entirely preventable,” said Southern Center for Human Rights attorney Sarah Geraghty. “Defendants had plenty of notice that conditions at Hays were life-threatening for prisoners and officers, but they ignored the problem. Consequently, RaHonda MacClain lost her only son.”