A citizen flagged an officer down on city streets and reported that white male was walking around the parking lot of a nearby Safeway store with a large knife in his hand. Officers checked the area and located a man matching the description walking toward the BART station bus zone. Officers detained the man and found that he had a large steak knife concealed in his waistband. Record checks also showed that he was on probation for burglary, out of Contra Costa County. Concord PD had no reports of any other crimes associated with the male suspect. Officers arrested the man for possession of a dirk/dagger. He was booked at the Martinez Detention Facility for possession of a dirk and probation violation.