Alphonso Michael Giardello Jr. is a fictional character from the television drama Homicide: Life on the Street.

Mike is stunned when the FBI allows a mobster in Witness Protection who has murdered a Baltimore resident to take a lenient plea deal because he's needed for a major Mafia trial in Philadelphia, and later resigns from the Bureau.

He was earlier left devastated when he was enlisted as a hostage negotiator when a deranged father was holding his son and daughter hostage, and the father ended up killing his son before committing suicide (though this episode aired after the one where he resigns from the FBI).

In the series finale he talks of returning to the Baltimore streets, and the 2000 TV movie reveals that he has joined the BPD as a patrolman in hopes of earning a detective's shield.

Michael remains proud of Al however mainly due to his accomplishments in blazing trails for African American officers in the BPD (Michael claims Al was one of the first black Lieutenants in the department and encourages Al to take the captain's position on the finale as a means of improving the bad relationship between the city's black community and the police department).