WASHINGTON (AP) — On foot and horseback, police went through a Washington park on Monday looking for the remains of Chandra Levy in a place she liked to visit. They came away empty-handed, frustrated anew in the 2-month search for the former federal intern.

Police cadets joined officers in the area around Klingle Mansion in spacious Rock Creek Park, about two miles from Levy's apartment. Police say Levy, 24, looked up a map site for the house on May 1, the last time she is believed to have used her laptop computer and a day after she was last seen in public.

Police have searched the area before in their hunt for Levy, Executive Assistant Police Chief Terrance Gainer said. They plan to search at least three other Washington parks this week.

Officers also continued to search abandoned buildings in the neighborhoods near Levy's apartment. They have looked through 243 buildings with no sign of Levy's body, Gainer said.

"The good news is we didn't find what we didn't want to find," he said.

The case has generated national attention because of the involvement of Rep. Gary Condit, a Democrat whose district includes Levy's hometown of Modesto, Calif. He has said he and Levy were friends, and, according to a police source, he has told investigators he was having an affair with her.

Condit, 53 and married, is not a suspect in Levy's disappearance, according to police, who classify the case as that of a missing person rather than a crime. Condit has kept a public silence but has talked with authorities three times.

Levy's mother, Susan Levy, has said she believes Condit may have more information he can share with investigators, and she has strongly urged him to cooperate with authorities.

"I just want my daughter home. I want her home soon, alive," she said Monday outside her home in Modesto.

Meanwhile, Condit critics plan a rally Tuesday outside his office in Modesto. They plan to call for Condit's resignation.

"We're going to keep on him until he's gone," said Saundra Duffy, the Fresno/Central Valley coordinator for the conservative group that runs the freerepublic.com Internet site. "There's no excuse for his behavior."

Police have four theories about Levy's disappearance: She left of her own accord, committed suicide, has amnesia or is the victim of foul play. Police have reported finding no signs of foul play in her apartment.

Police say the suicide theory becomes more unlikely as time passes because a body has not been found. Last week, police released computer-generated pictures of Levy showing how she might look if she changed her hairstyle.

Levy was last seen when she canceled her membership at a health club April 30. She was making preparations to return home to attend her graduation ceremony at the University of Southern California.