After two weeks of fruitless searching for a man they called a material witness, authorities Saturday officially made him a suspect in the nation's first fatal bombing of an abortion clinic.

Federal agents also offered a $100,000 reward in the case and pleaded with Eric Robert Rudolph, 31, to turn himself in."We are concerned about the situation for everyone involved, including Eric," said Jim Cavanaugh, an Alcohol, Tobacco and Firearms agent. "This would be a lot easier on everyone involved if he would contact us and come in."

Rudolph's truck was spotted near the New Woman All Women Clinic in Birmingham on Jan. 29, the morning an explosion killed an off-duty policeman working as a security guard and critically injured a nurse.

U.S. Attorney Doug Jones announced the change in status for Rudolph during a news conference in Birmingham. Rudolph faces charges with using an explosive device to damage a building, which carries a penalty of life in prison or death.

The decision to move ahead with criminal charges against Rudolph came after agents examined evidence seized from his home, storage locker and truck, Jones said.

Rudolph's truck was found abandoned last weekend south of Murphy, N.C., his hometown and the hub of the search. Rudolph hasn't been seen since Jan. 30, the day after the bombing, when he rented a video and bought something to eat in Murphy.

Authorities said he may be receiving help from someone, or he may be on his own, relying on his skills as an outdoorsman to hide in the mountainous North Carolina wilderness.

"That's his home, and that's probably where he's most comfortable," said Joe Lewis, FBI Special Agent in Charge in Birmingham.