Amid widely publicized complaints about ill-treatment of transgender inmates in Georgia prisons, federal officials have begun an investigation into the treatment of LGBT inmates generally in the state’s prisons.

The U.S. Department of Justice’s Civil Rights Division and the U.S. Attorney’s office for the Northern District of Georgia are jointly conducting the probe into institutions operated by the Georgia Department of Corrections, the Georgia Voice reports. This is the first Justice Department investigation to focus on the situation of LGBT prisoners.

“Essentially we’re looking at potential violations of the Civil Rights of Institutionalized Persons Act, which deals with the constitutional rights of prisoners in institutions like prisons,” U.S. Attorney John Horn told the Voice.

High-profile cases in Georgia include those of Ky Peterson and Ashley Diamond, but officials wouldn’t say if the investigation was motivated by these particular situations. “What we can say is that we have received some complaints relating to allegations of abuse in Georgia prisons,” Horn said. “When we reach critical mass, we decide to open up an investigation.”

Peterson, a transgender man, has spent nearly five years in a women’s prison for killing his rapist, an action he says he took in self-defense. Until recently, he was denied hormone therapy, and he says he has been subjected to much hostility from guards at Pulaski State Prison. He has spent time in “protective custody,” that is, solitary confinement.

Diamond, a trans woman, also was denied hormone treatment and spent time in solitary confinement during the three years she served in all-male prisons for a nonviolent burglary and theft conviction. She has further alleged that she was repeatedly sexually assaulted. Represented by the Southern Poverty Law Center, she filed a federal lawsuit against the Georgia DOC in February 2015; it was settled out of court a year later. Diamond was released from prison last August.

It was after the settlement that Georgia prison officials began offering hormone therapy to Peterson and other trans inmates. They also put in place policies aimed at preventing sexual assault and meeting the health and safety needs of these prisoners, the Voice notes.

“While our lawsuit has done an important part of the work of making conditions in Georgia safer for prisoners, the Department of Justice is going in behind us with a focus specifically on safety and housing issues with respect to that community, and sexual victimization risk,” Chinyere Ezie, Diamond’s attorney at the SPLC, told the Voice.

The investigation is in its early stages, but the Georgia DOC has been cooperative, Horn told the newspaper. “We’re working closely together to conduct the investigation quickly and thoroughly,” he said.