West Valley police were looking Monday for the person who robbed a Smith's store, apparently by going through the ceiling.

About 5:15 a.m. Monday an employee of Smith's, near 4100 S. Redwood Road, was counting receipts when she had to go to the gas station outside to pick up its money, said West Valley police Capt. Tom McLachlan.

She locked her office door and was gone for 10 minutes. But when she returned, the cash was gone and a ceiling tile removed, he said.

Investigators say the theft likely was carried out by someone who knew the layout of the building and the employee's daily routine.

Forensics detectives searched the office Monday looking for fingerprints and other possible evidence, McLachlan said.