The search for missing 8-year-old Washington, D.C., girl Relisha Rudd has been shifted to a "recovery mission," police said, indicating they're considering the possibility she's dead. D.C. Police Chief Cathy L. Lanier said Thursday that the department hasn't lost hope that Relisha is still alive after disappearing about a month ago. Officials issued an Amber Alert for her disappearance March 20 and suspect Kahlil Malik Tatum of abducting her. "We cannot ignore the possibility that he may have killed her," Lanier said. On Friday, the FBI and D.C. police searched a heavily wooded park in northeast Washington. Lanier said the search would continue over the weekend in the Kenilworth Park area, which covers about 700 acres of land and includes small bodies of water. Police are searching the area after discovering Tatum spent more than two hours near the park after purchasing 42-gallon contractor-style garbage bags March 2. Tatum worked at the homeless shelter where Relisha, and her mother and stepfather were staying. Police discovered Tatum's wife, Andrea Denise Tatum, dead in a motel room March 20, the same day the Amber Alert for Relisha was issued. Tatum has been charged with murder in his wife's death. Relisha had allegedly been left in the care of Tatum about a month ago.