Alberta RCMP are now part of an international manhunt for two US fugitives considered extremely dangerous.
It's believed the couple are in Montana and could be trying to enter Canada.
RCMP are already acting on tips that the couple could be in Canada.
Sgt. Patrick Webb of the Alberta RCMP says, "There are less than five tips, possibly three sightings in Canada. In this case we checked them all out and found no evidence had crossed into Canada."
RCMP have moved their helicopter to the Alberta/US border as a precaution.
Police warn the escapees are extremely dangerous and may have killed on the run.
The charred remains of retirees Linda and Gary Hass were found at a campground in New Mexico.
Barrett Marson of the Arizona Department of Corrections says, "They are to be considered armed and dangerous. There is forensic evidence that ties them to a double homicide in New Mexico."
Tuesday, the US search focused on the west part of Montana.
US Marshall Tom Henman says, "Numerous teams of US Marshalls and other investigators are following up on leads in those areas. We're also working with US border patrols, immigration and customs on our side to keep an eye on their border."
It started with a prison break on July 30th.
Three inmates, John McCluskey, Tracy Province and Daniel Renwick escaped from an Arizona jail.
Police believe they were aided by Casslyn Welch.
Renwick was caught two days later in Colorado.
Province was captured near Yellowstone national park in Wyoming on Monday.
It's believed McCluskey with alleged accomplice, his cousin and fiancée, Casslyn Welch have now moved north.
US Marshalls have also notified Calgary police of the manhunt.
