An Atlanta doctor contracted by the District of Columbia Jail pled guilty Tuesday to sexually assaulting an inmate who was seeking medical care, authorities said.

Lewis Jackson, formerly of Washington, D.C., was indicted on a second-degree felony of sexual abuse after DNA evidence confirmed the 2008 assault, District police said.

Within weeks of the D.C. indictment, an Atlanta, Ga. federal court indicted Jackson for similar crimes committed in an Atlanta federal penitentiary. Jackson, 36, admitted to sexually assaulting three inmates there.

Jackson will be sentenced in Atlanta in February and in the District later this year.