PHOENIX -- Police are searching for the suspect in an armed robbery of a north Phoenix grocery store.Shortly before 12:30 p.m. March 8, a man was seen shoplifting detergent and other unknown items from the Albertsons store near Cave Creek Road and Union Hills Drive.Police said an employee confronted the man but backed away when he displayed a knife. The man walked out of the store, carrying a plastic card in his mouth.The suspect is described as a 6-foot tall, 160-pound Hispanic man between 25 and 35 years old. He has dark hair, a beard, sideburns and a mustache. He also has a tattoo on the right side of his neck.Anyone with information is asked to contact Silent Witness at 480-WITNESS or 1-800-343-TIPS (toll free). Anonymous tips can also be submitted online at www.silentwitness.org.Witnesses could be eligible for a reward of up to $1,000.