PHOENIX (AP) — The U.S. Marshal's Service says a dangerous Arizona fugitive and his fiancee are unpredictable and have the ability to move quickly.

U.S. Marshals followed tips Wednesday that the pair was in Arkansas and may have robbed a beauty supply store.

Fidencio Rivera, the Chief Deputy U.S. Marshal for Arizona, says they are continuing to investigate leads in Arkansas. But he says the inmates may still be in Montana, or elsewhere.

He says John McCluskey and Casslyn Welch are reacting to their circumstances and are willing to rob to get the resources they need to remain on the run.

Federal officials believe the pair are driving a 1997 Nissan Sentra.