Dive teams plunged into the waters of Kenilworth Park and Aquatic Gardens on Saturday, resuming a search for 8-year-old Relisha Rudd, whose disappearance since March 1 has gripped the city and revealed problems in the District’s main homeless shelter.

D.C. police spokesman Hugh Carew said dive teams were searching the Anacostia River in the 700-acre park in Northeast Washington. A foot search will resume Monday, he said.

Relisha was last seen March 1 with Kahlil Malik Tatum, a janitor from her homeless shelter who police think abducted her. The next day, police said, Tatum bought a box of 42-gallon trash bags and was seen spending time in Kenilworth Park.

On Thursday, Police Chief Cathy L. Lanier said that although police remain hopeful that Relisha is alive, the search had become a “recovery mission” and they could not ignore the possibility that Tatum had killed the girl.

Relisha, a student at Payne Elementary School, lived with her mother and three younger brothers at the old D.C. General Hospital, where she was enrolled in the Homeless Children’s Playtime Project. In late February, Relisha’s mother, Shamika Young, allowed Tatum to look after her daughter and told people that the girl was in safe hands, according to police.

But by mid-March, Relisha had missed about a month of classes. School officials had excused many of those absences because the family produced a note saying she was with someone named “Dr. Tatum.” It was not until March 19 that social workers discovered that “Dr. Tatum” was not a doctor.

Police think Tatum fatally shot his wife, Andrea Kelly Tatum, in an Oxon Hill motel room the night of March 19 or the next morning.

Since then, he has vanished. Authorities have offered a $45,000 reward for information leading to his arrest and prosecution, as well as a $25,000 reward for Relisha’s safe return. A D.C. Superior Court grand jury is also investigating possible obstruction of justice charges against Young, 27, according to people familiar with the case.