"I think they've taken the persona that this is some type of movie and this is some kind of a joke that they are living, but it is not," Gonzalez said. "This is a very, very serious business."
While investigators have their sights trained on the surrounding area of Yellowstone, it is still a "national manhunt." Investigators said that the couple is driving a gray Nissan Sentra.
U.S. investigators also alerted the Royal Canadian Mounted Police that the escapees may have headed north into Canada, the AP reported.
The investigation into how the prison escape occurred July 30 is ongoing. Security lapses have been blamed.
Authorities say Province and McCluskey escaped from a medium-security Arizona prison July 30 with the help of Welch.
The search intensified for the remaining fugitives this weekend after forensic evidence linked at least one of them to a double-murder in New Mexico.
Gonzalez said Province and McCluskey are suspects in the double-murder of a husband and wife who were burned in their trailer in New Mexico last week. The charred remains of Linda and Gary Haas were found last week after a rancher came across their wandering dogs. The couple's truck was found 120 miles away in Albuquerque with evidence connected to the escapees, police said.
McCluskey's mother is now under arrest for allegedly giving McCluskey and Welch clothing, money and a getaway car.
McCluskey's stepfather, Jack Washburn, expressed his anguish at the pain his step son has casused.
"He'll never realize how bad he's hurt me and his mother," Washburn said.
CLICK HERE to see a picture of each of the runaways at the U.S. Marshal website.
The Associated Press contributed to this report.