A former UND student pleaded guilty Monday to an unprecedented series of rapes in Grand Forks in an agreement that could keep him from spending the rest of his life in prison.

Paul Sambursky, 29, pleaded guilty to five charges of felony gross sexual imposition, or rape, and one misdemeanor charge of disorderly conduct related to what prosecutors said was an aborted sexual assault.

The plea made with prosecutors essentially solves the case of the serial rapist who ambushed six random victims from Oct. 16, 2001, to Nov. 27, 2002 - three on campus, three off campus, including one just south of Grand Forks. Law enforcement officials say there hasn't been another rape case like it solved in the city.

Monday's guilty plea was a big change for Sambursky, who was a criminal justice major and vice president of UND's Criminal Justice Association until he was arrested in March. The ex-Marine at first strongly denied the charges through his attorney and collected affidavits from neighbors and colleagues testifying to his churchgoing character.

In July, Sambursky pleaded not guilty to the same six charges. He was charged with three Class A gross sexual imposition felonies, each with a maximum sentence of 20 years; two Class B gross sexual imposition felonies, each with a maximum sentence of 10 years, and a Class B misdemeanor of disorderly conduct - with a maximum sentence of 30 days - for an attack that fell short of the definition of felony sexual assault.

During Monday's short hearing, Sambursky agreed to plead guilty to all six charges. In return, prosecutors will recommend that he be sentenced to a total of 80 years and 30 days on the consecutive sentences, with 60 years suspended, said Rick Brown, the assistant Grand Forks County state's attorney who has handled the case from the beginning.

"We felt that because each of these things occurred over a span of time, they should be treated separately," Brown said. "Certainly, they would all have been separate trials."

If Grand Forks District Court Judge Debbie Kleven accepts the recommendation, Sambursky would serve 20 years and 30 days in the state prison, probably with a substantial probation period to follow, Brown said.

"He could have faced 80 years, but he has no prior record," Brown said, explaining his reasoning in reaching the plea agreement. "Some of these were violent, and some weren't quite as violent."

Kleven set Dec. 4 for sentencing.

Lee Finstad, Sambursky's attorney, could not be reached for comment Monday evening.

DNA evidence from three of the assaults, processed by the state crime lab, was "invaluable" in making the case against Sambursky, Brown said. In one of the assaults, the victim immediately sought help and suggested that saliva from Sambursky might be retrievable from her chest area. Her quick thinking resulted in the first DNA evidence garnered against Sambursky, officials said.

Brown and police investigators praised the female victims, saying their bravery and cool-headedness in fending off the attacker and the fact that they sought immediate medical and police help made the case against Sambursky.

The victims described their attacker accurately and identified him visually during the investigation, police said. Plus, their accounts of what he said and did during the attacks were very similar, first tipping investigators that this was a serial rapist. One accurately described Sambursky's car. Several of the victims suffered injuries, but none were major; Sambursky threatened them all with violence.

Brown said he has kept the victims of Sambursky's assaults informed of the plea agreement and is confident they approve of the deal.

"One of the victims was here today," he said. "It's a very emotional thing."

Two of the sexual assaults and the misdemeanor incident happened on the bike path along the English Coulee on UND's campus. Two assaults happened off campus in Grand Forks; one near University Park and one on Cherry Street. One assault happened in a car just southwest of Grand Forks.

Days after being charged, Sambursky was kicked out of classes and removed by UND officials from his job as a lab assistant to a physics professor. He also was barred from living in UND family housing with his then-wife and four children.

"I think the victims will be happy to have this behind them," said UND Police Chief Duane Czapiewski. "As far as the university is concerned, we are glad it's an issue we can bring to resolution and hope we can make the campus safer again."

Several other sexual assault incidents were investigated but were not linked to Sambursky, Czapiewski said. "Any previous cases we have reviewed did not fit the same method of operations, so probably he's not involved in those."

Brown said he knows of no solid evidence linking Sambursky to any other sexual assaults.

Sambursky has remained in the Grand Forks County Correctional Center, under $180,000 bond, since he was arrested in March.

Sambursky has "stated a willingness to make restitution to any of the victims for any treatment," related to the assaults, Brown said.

Sambursky's assaults were not immediately linked as part of a serial rapist, partly because some were done on campus, some off campus, in the jurisdiction of either the Grand Forks Police or the Grand Forks County Sheriff's Department.

Czapiewski said all three departments have made efforts to improve communication to link such crimes faster.

"That occurred earlier this fall when we had a number of vehicles broken into," he said. A stop by a city police officer led to breaking the case of the campus break-ins, Czapiewski said.

Already this semester, two sexual assaults on campus have been reported, he said. Both have been reported to be "acquaintance rape," situations, where the alleged perpetrators' identities are known, and the cases are being investigated, he said.

Meanwhile, his officers patrol the bike path where Sambursky attacked three women.

"It's an unusual place, a beautiful nature walk, a nice place to jog," Czapiewski said. But it's important that "at least two people go together for their own safety," when using the bike paths on campus, he said.