Dark Blue (season 1)

Carter Shaw is the head of a crack undercover team of police officers who are so covert, many of their own colleagues don't even know they are involved. Shaw is a deeply wounded character, having lost his wife and much of his former life as he struggles to bring down bad guys through complex undercover assignments. His team includes a recently married cop who struggles with personal relationships he has developed while undercover; a shoot-from-the-hip officer whose activities make fellow team members wonder if he has gone over to the bad side; and a green patrol cop brought in because of her excellent skill in lying and a shady past.