PROVO — Police are looking for a man who might be the culprit behind two armed robberies — one successful and one foiled — Saturday night.

Just after 6:30 p.m. a man walked into the Crest Convenience Store at 700 E. 800 North in Provo brandishing a gun and demanding money, said Provo Police Capt. Cliff Argyle.

The clerk told the man he didn't think the gun was real and refused to give him money, Argyle said. The man threatened to shoot the clerk, who still refused, based on the belief the gun was fake, Argyle said.

Failing to get any money, the man left the store and ran north.

The clerk, who didn't know if he should call police or not because the man didn't get any money, finally called 911 just after 9 p.m., Argyle said.

The clerk described the man as Caucasian, approximately 6 feet 2 inches tall, with a slim build. He was wearing a black ski mask and carried a semi-automatic weapon in his gloved hands, Argyle said.

Police are also investigating an incident at 7:45 p.m. that same night, where a man walked into the Subway Sandwich Store at 148 W. Bulldog Blvd. and demanded money while threatening the female clerk with a gun, Argyle said.

The woman took money from the register and gave it to the man, who fled the site.

There were no surveillance tapes from either burglary, but the female clerk described the man as an adult Caucasian, about 6 feet tall, wearing a black ski mask and black gloves, Argyle said.

"Because of similarities in these cases we believe that the same individual may be responsible for both," Argyle said.

Call Provo police with tips at 801-852-6210.