A clerk at the Blue Ribbon Grooming in Fort Smith, called police last weekend saying that a young, white man demanded money from the cash register and threatened her with a knife. The suspect had been in a couple of times that morning asking for water and to use the phone, according to the clerk. The alleged robbery happened the third time he came in. The suspect grabbed the business' phone and threw it on the floor, after getting the money from the register. Authorities were able to identify a 17 year old boy as the suspect, during the investigation. The boy was then interviewed and arrested for aggravated robbery. He was also connected to a July 2nd commercial burglary at the Apple Market on North 6th. According to police, the teen is being held in the Sebastian County Detention Center on those charges, along with a warrant for Theft of Property out of Crawford County.