Police arrested a Crookston, Minn., convicted sex offender Monday night and charged him with kidnapping in the disappearance of Dru Sjodin (search), police spokesmen said.

Alfonso Rodriguez Jr., 50, was arrested in Crookston (search) and was being held in the Tri-County Correctional Center, Grand Forks police said. Rodriguez was scheduled to appear in court Tuesday in Crookston.

Sjodin, a 22-year-old University of North Dakota (search) senior last seen Nov. 22, has still not been found.

According to the Minnesota Department of Corrections Web site, Rodriguez has a history of sexual contact with and attempted kidnapping of adult females while using force and a weapon. He was previously known to one victim but not two others.

He was released from prison in May after serving a sentence for aggravated rape, attempted aggravated rape, attempted kidnapping and aggravated assault, according to the Web site.

His past offenses require that Rodriguez be registered as a predatory offender, the department said.

Police said a search for Sjodin was continuing, and said no other information would be released until an 11 a.m. news briefing Tuesday.

Sjodin, of Pequot Lakes, Minn., was last seen as she left her job at the Columbia Mall in Grand Forks (search), about 30 miles from Crookston. Her 1994 red two-door Oldsmobile Cutlass was found in the mall parking lot.

Sgt. Michael Hedlund had said earlier Monday a crime lab analysis of the car yielded nothing.

Soon after the young woman disappeared, her boyfriend, Chris Lang, called Sjodin's roommate, saying he had received two calls. The first was cut off and Lang heard Sjodin say, "Oh, my God," before the phone went dead.

A second call a couple of hours later was filled only with static and the sound of numbers being pressed.

Since then, more than 1,300 volunteers have been involved in the search for Sjodin, using all-terrain vehicles to plow through ditches and fields in the Grand Forks area. Divers searched the Red Lake River near Crookston.

In addition, about 30 FBI agents, along with investigators from 20 agencies in three states and the Canadian province of Manitoba, were involved in the case. A $140,000 reward was offered.

At a news conference with police earlier Monday, Sjodin's mother, Linda Walker, in radio and television interviews, said her family has been overwhelmed.

"We're going to find you, Dru," said one cousin, Mike Sjodin.

The news of the arrest was stunning -- coming just hours after the family's appearance with police.

One of Sjodin's cousins, Jon Sutfin of Washington, D.C., said the family had remained upbeat during the grueling two weeks of her disappearance. "We look at it as a countdown to finding her," Sutfin said.

Police have said they received more than 900 calls to a tip line, and more than 5 million hits to a Web site set up to help in the search.

The woman's brother, Sven Sjodin, 24, a finance manager at a California car dealership, said the family has heard from people around the world. In the Grand Forks area, strangers have given hot chocolate, food and gasoline.

"The outpouring of support from people has been tremendous," the brother said.

Neighbors said Rodriguez lived with his mother, Dolores. No one answered the phone at the home Monday night. His neighbors said a town meeting was held in May to inform them about his release from prison.

Sonja Thygeson, who lives about four houses down from Rodriguez and his mother, said she's never seen him do anything wrong, but took precautions anyway.

"I'm a widow and I'm older, and I was scared, so I had my son-in-law come over and install a motion light after he (Rodriguez) moved in," Thygeson said.

Another neighbor, Milton Stave, said "there were a lot of frightened people around" when Rodriguez returned to the community.

The Associated Press contributed to this report.