Erie Police Chief Randy Bowers confirmed Kyle Johnson was found dead in his cell Sunday, according to ABC sister station WJET-TV.
Johnson's death came shortly after he was charged with murder Saturday in the death of 58-year-old Kum Miller of Pennsylvania.
Police say the medical examiner has been called, WJET-TV reported.
Initially, authorities said Miller had been critically injured after Johnson allegedly broke into her home in Erie, Pennsylvania on Tuesday. Police documents said he used a crowbar to beat Miller.
Murder and criminal homicide charges were the most recent among a total of 10 charges Johnson was facing.
Johnson allegedly hid his ex-girlfriend, Brandi Shakir, 23, of Oakwood Village, Ohio, in Miller's basement.
Authorities had been searching for Shakir since Johnson allegedly abducted her Monday.
