Police say the man suspected of a triple-murder and armoured car robbery was arrested peacefully Saturday night, ending a massive 36-hour manhunt.

"It was the best outcome we could have hoped for," Edmonton Police Supt. Bob Hassel told a news conference Sunday afternoon.

Hassel said the suspect, 21-year-old Travis Baumgartner, is currently in police custody in Langley, B.C. Baumgartner is expected to be transferred back to Edmonton within the next week. He faces three counts of first-degree murder, one count of attempted murder and four counts of armed robbery.

Baumgartner was detained by U.S. border officials and arrested by the RCMP late Saturday night trying to cross into Washington state from Abbotsford, B.C. He was found with roughly $330,000 in his pick-up truck at the time of the arrest. Police could not say whether any weapons were found in the vehicle.

Hassel said a team of eight investigators -- five homicide investigators and three forensic investigators -- flew into Langley Saturday night.

"They're sifting through the evidence, including the suspect's vehicle. They're doing that as we speak," said Hassel.

Edmonton Police notified border officials and the RCMP within four hours of an armoured car robbery at the University of Alberta Friday that left three security guards dead and one in critical condition.

Hassel said he has been in contact with all of the victims' families, as well as with Baumgartner's mother.

"Everyone is now relieved that he's in custody," said Hassel. "Quite frankly I'm happy with the way it ended, that it ended peacefully."

A news conference to update the media on the investigation is scheduled for Monday 11 a.m. local time (1 p.m ET).

"We're grateful to the border officials at Lynden, Washington, for their excellent work in arresting a man we believe was armed and extremely dangerous," Hassel said on Saturday, shortly after the arrest.

Police allege Baumgartner was part of a crew of five guards with the security company G4S who were re-loading an ATM machine at the Edmonton campus early Friday morning, when the robbery took place. Four of the guards were shot and three died. The fourth remains in critical condition.

Police later found an armoured car close to the G4S depot that had been left running and had its lights on.

In a statement issued Friday, Baumgartner's mother had begged her son to turn himself in.

"Please, Travis, I love you and I'm pleading with you with all of my heart to end this without further bloodshed," Sandy Baumgartner said in the prepared statement.

In her statement, his mother urged him to "come forward now and take responsibility for your actions," adding that she would offer him support. She also apologized for having an argument with him just before he left for his Thursday night shift.

Neighbour Joyce Stewart said her heart goes out to Baumgartner’s mother.

“I can’t imagine how she feels,” Stewart told CTV Edmonton. “He’s her boy and she loves him.”

The guards killed in the Friday morning robbery were Eddie Rejano, 39, Michelle Shegelski, 26, and Brian Ilesic, 35.

Shegelski had worked for the security company G4S for several years and was recently married. Her family described her as a warm, bubbly person who was always smiling.

“We’re just so caught up in the grief and the loss and I guess the senselessness,” said Shegelski’s uncle John Ernst.

“I see this as just the beginning for us. The families of the victims are usually the ones that have to struggle for years and years with this type of crime.”

Ilesic had a 12-year-old daughter.

Rejano was a competitive target shooter and worked a second job as a gun range officer at the Wild West Shooting Centre at West Edmonton Mall.

He was striving to join the Edmonton police service.

Matthew Schuman is listed in critical condition in hospital. He is an Air Force firefighter. G4S was his second job.

A spokesperson for G4S, an international security company with more than 630,000 employees, said the company will continue to aid officers with their investigation.

"We applaud the dedication of the Edmonton Police Service, and other law enforcement agencies in apprehending Travis Baumgartner today," Robin Steinberg said in a statement.

"Our thoughts remain with the families and friends of the victims and also with the Baumgartner family."

The company has also launched its own investigation into the incident.

With files from The Canadian Press and a report from CTV Edmonton’s Sean Amato