The University of Alberta shooting suspect at the centre of an international manhunt was arrested Saturday while attempting to cross the U.S.-Canada border.

Police say Travis Baumgartner, 21, was caught at the Lynden, WA U.S.-Canada border south of Abbotsford, B.C.

Police say Baumgartner was arrested while driving his dark blue Ford F-150.

Sources tell CTV News he was using his mother's license plate and did not have a passport.

"We're hearing the vehicle still had his mother's licence plate on it," EPS Supt. Bob Hassel said in police statement issued shortly after news of the arrest.

"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."

Police are now in the process of bringing Baumgartner back to Edmonton.

Baumgartner is a G4S Security armoured guard suspected to have shot and killed three of his armoured guard colleagues and put a fourth guard in hospital with life-threatening injuries.

Canada-wide warrants had been issued for Baumgartner's arrest.

He faces three counts of first-degree murder and one count of attempted murder.

Police says news of the arrest has brought some level of relief to the G4S family.

"We applaud the dedication of the Edmonton Police Service, and other law enforcement agencies in apprehending Travis Baumgartner today," G4S spokesperson Robin Steinberg said in a release.

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

"We will continue to cooperate fully with the Edmonton Police Service, while conducting our own detailed investigation into the incident. Once again, we would like to thank our customers, employees and the community in general for their continuing support during this difficult time."

G4S employees Michelle Shegelski, 26, Brian Ilesic, 35, and Eddie Rejano, 39, were shot and killed in HUB Mall at the U of A Friday.

A fourth victim Cpl. Matthew Schuman, 26, remains in hospital with life-threatening injuries.

Police are expected to update media on the case Sunday afternoon.