STAMFORD-The Stamford police K-9 Unit on Monday retired expert tracker Titan after six and one-half years on the job with his handler officer Mark Tymon. K-9 Unit Sgt. Seth O’Brien said that the German Shepherd had served the department very well in his time and was now 10 years old and it was time for him to hang up his bulletproof harness. O’Brien said that police dogs often retire between eight and 10 years old and he retired his own dog, Cooper, the last dog to in the department to step down after he turned 10 this past November.