A former prison doctor is facing federal charges for the alleged sexual abuse of inmates in his care.

Lewis Jackson, 30, of Atlanta, was arraigned Thursday following his Aug. 28 indictment by a federal grand jury, U.S. Attorney Sally Quillian Yates said.

Jackson allegedly molested three inmates seeking medical treatment at the U.S. Penitentiary in Atlanta, where he worked from January 2011 until July 2012, Yates said. The defendant faces three counts of sexually abusing a ward and one count of lying to federal agents.

“His actions betrayed the trust placed in him to provide appropriate medical care to federal prisoners during their incarceration,” Yates said in an emailed statement.

If convicted, Jackson could be sentenced to up to 15 years in prison and ordered to pay a fine of up to $250,000, the U.S. Attorney’s office said.

In a related case, Jackson was charged last week in the Superior Court of the District of Columbia with three counts of sexually abusing another inmate in 2008, Yates said. According to that indictment, Jackson performed a series of sex acts on the inmate after he sought medical treatment while in jail.

Jackson was on bond in the Washington case at the time of his arrest in Atlanta. His trial in the D.C. case is set to begin Jan. 17.