CHADRON, Neb. - Five men, including two who had walked away from a corrections facility Monday in Helena, Mont., were arrested Thursday morning in Chadron after a force of more than 50 law enforcement officers mounted a massive search.

The five are suspects in the armed robbery of a casino on the

Nebraska-South Dakota border that took place shortly after 10 p.m.

Wednesday evening. The casino is about 20 miles north of Chadron, on

U.S. Highway 385.

The arrests, about 10:45 a.m., ended a lockdown that had virtually brought life to a halt in this community of 6,500 in northwest Nebraska since the early morning hours.

At a news conference Thursday afternoon, Chadron Police Chief Tim Lordino identified the suspects as Jordan Lee Adams, Jacob Edward Kraus and Camille James Adams. The three were apprehended following a tip from a local resident.

Lordino said he was unable to positively identify the other two men, and would release their names later.

Jordan Adams, 19, and Jacob Kraus, 20, had both walked away from the Montana pre-release center on Monday. Adams was serving a three-year sentence for an August 2006 robbery. Krause was serving a three-year sentence for a May 2006 burglary.

Camille Adams, Jordan Adams' 21-year-old cousin, was on probation for a 2004 robbery when he walked away from the Butte, Mont. Pre-release center in 2005. He was sentenced to two years for the escape and released in March to complete his probation.

The three are believed to be responsible for armed robberies of convenience stores in Butte and Columbus, Mont. on Tuesday, and of a convenience store in Sheridan, Wyo., early Wednesday.

Chadron law enforcement learned of the casino robbery Wednesday night from a customer who had been in the adjacent restaurant when the robbery took place.

A Chadron police officer attempted to stop the vehicle as it came into town, but was unsuccessful, Lordino said. The men abandoned the vehicle a short time later in a residential area about five blocks from Chadron State College, he said.

Informed of the situation about midnight, Chadron State College officials began a lockdown of the campus, according to Randy Rhine, vice president for student enrollment. The doors to all five resident halls, which house about 700 residents, were locked, and nobody was allowed to enter or leave, he said.

Residence hall directors and assistants went door to door to inform students of the situation. Two individuals involved in separate instances told them that five men had approached them and offered a large amount of cash to take them to a gas station, according to Rhine.

"Apparently, they were trying to get a ride to a car," said college president Janie Park. "The students who were approached did a good job of assessing the situation and walking away. I was grateful they weren't that trusting."

By that time, Chadron police, assisted by officers from the Nebraska State Patrol and other adjacent law enforcement agencies, had all roads into and out of town closed and were calling for reinforcements to their search.

Classes at the college and Chadron public schools, as well as schools in nearby Crawford and Hay Springs, were canceled, and police asked businesses to remain closed as well. The local Wal-Mart store was locked down and the 24-hour McDonalds restaurant was closed, and two all-night convenience stores that had been alerted to the situation remained open.

The state patrol had a single-engine aircraft in the skies over Chadron from about 5 a.m., and streets that normally come alive a short time later in the morning remained largely deserted.

By 9 a.m., the Pennington County Sheriff's Office-Rapid City Police Department Special Response Team of more than 20 members from Rapid City had arrived to help with the search operation.

A tip from a citizen who saw the five men in an area of west central Chadron, narrowed the search down, and four of the suspects were arrested a short time later near the Prairie Pines assisted living center, according to Lordino.

The fifth was found not far away after the officers narrowed their search to an area of abandoned trailer houses and used dogs in the pursuit.

One firearm and an undisclosed amount of cash was taken from the suspects, Lordino said.

Among the charges initially filed against the men are possession of a stolen firearm, felony possession of stolen property and felon fleeing to avoid arrest. The men were taken to jail in Scottsbluff, and other charges are pending, he said.

The massive law enforcement effort that led to the arrests included the Chadron Police Department, Dawes and Sheridan County Sheriff's departments from Nebraska, and Fall River County Sheriff from South Dakota, Nebraska State Patrol, police from Crawford, Scottsbluff, Gering and Alliance in Nebraska and Rapid City, S.D., Nebraska Game and Parks, and U.S. Department of Wildlife.

Lordino said he was particularly impressed with the cooperation among the multiple agencies and the help from the community, that led to a successful outcome.

"The amazing thing is nobody got hurt," he said.

The college staff and students also responded well, according to Park, who said that the college had recently reassessed its security plans in the wake of the shootings at Virginia Tech. "We try to respond appropriately, but locking down the campus is a new thing for us," she said.

Although the college is looking at adopting a system that can use text messaging and other electronic media to alert students to security issues, Wednesday's situation was handled with a phone tree people knocking on doors and a posting on the college Web site, she said.

"We are a small enough campus we can do that," she said. "It was a great test, and it had a good outcome."