PORTLAND – Authorities are making arrangements to extradite two people suspected in the murder of a Canadian tourist, but it’s unclear when the pair will be back in Maine.

Benjamin Humphrey, 29, and Aimee Pelletier, 23, are being held at the Pennington County Jail in Rapid City, S.D. They were arrested in a Rapid City shopping mall following a five-day, nationwide search.

Humphrey is charged with the murder of 47-year-old Derek Rogers of Russell, Ontario, who was fatally beaten in Old Orchard Beach on July 31.Police believe it was a random act of violence.

Pelletier, Humphrey’s girlfriend, is charged with hindering apprehension. Police accuse her of helping Humphrey escape and tampering with evidence at the crime scene.

Maine State Police Sgt. Matt Stewart said their arrival date remains unknown because the details about transporting them are still being worked out with the U.S. Marshals Service.

“I expect that over the next several weeks, they will be brought back to Maine,” he said.

Police identified Humphrey as the suspect Aug. 10. They say Pelletier witnessed the attack, along with an unnamed female and young adult male.

Police believe Humphrey was headed to South Dakota because he has ties to people living on the Rosebud Indian Reservation, about 180 miles from Rapid City.

The pair were arrested last week after Pelletier called her mother and said she was scared and wanted to surrender. Pelletier’s mother then contacted Maine State Police.