NEW YORK — The New York Police Department is welcoming a newcomer that's the first of his kind for the nation's largest police department: a former military service dog.The 4-year-old German shepherd named Caeser served three tours of duty overseas. Now he'll be patrolling the New York City subways with Officer Juan Rodriguez.The Defense Department has long made some of its retired dogs available to law enforcement agencies, but the NYPD hasn't had one before. The arrangement saves the police force the $6,000 to $8,000 cost of training an inexperienced dog.NYPD Sgt. Randy Brenner is a member of the NYPD Transit Bureau's Canine Unit. He says military dogs make promising police partners, because they're "already used to working in stressful situations."