Michael (Mike) Logan was born in 1958 in New York City's Lower East Side into a working-class Irish-Catholic family. His father was also a police officer. He spent 10 years attending Our Lady of Mercy, where he was often in trouble and sent to see the guidance counselor. He is originally portrayed as a cocky, womanizing misanthrope with a short fuse, which his captain, Donald Cragen, refers to as his "famous temper". He is a now-retired homicide detective who worked for the New York City Police Department.