A convicted police impersonator is back in custody after an FBI search found him with a fake government ID. The San Francisco Chronicle says 21-year-old Max Horowitz of Oakland was arrested last week for violating his probation following a March conviction of pretending to be a federal cop. A tip from a Hayward police supply store led to a search which found him with uncovered cop business cards, forged law-enforcement documents and a dog commonly used in police canine breeding. Horowitz was previously kicked out of the police academy after only three days for violating unspecified rules.