The former Windsor Locks police officer accused of hitting and killing a teen last year wants his job back.

Michael Koistinen, 26, who is facing manslaughter charges in the death of Henry Dang, 15, has filed a grievance claiming he was fired from his job illegally.

Koistinen was driving just before midnight Oct. 29, after a night of drinking, according to state police. He hit Dang as the teen was riding his bike, investigators said.

On Sept 6, Koistinen appeared before the State Board of Arbitration and Mediation and claimed the Windsor Locks Police Commission illegally fired him, according to Scott Jelescheff, a lawyer for the International Brotherhood of Police Officers. He is asking to be reinstated and receive back pay for the time he has been off the force.

The Police Commission said it had the right to fire Koistinen in December, because he was still a probationary officer at the time of the accident, and could be fired for any cause. Jelescheff told NBC Connecticut, that Koistinen's probationary period ended Oct. 25, 2010, four days before the accident. He said the Police Commission didn't have the right to fire Koistinen without a proper hearing first.

On the night of the crash, Koistinen was taken from the scene by his father, Robert Koistinen, also a Windsor Locks police officer. He was never given a breathalyzer test or a blood alcohol test at the hospital after the accident. Robert Koistinen was later arrested and charged with obstruction of justice.

State police investigators, who took over the investigation, determined Michael Koistinen had been drinking for several hours before the accident. Investigators on the scene also found a glass containing beer, that a witness said Koistenen tossed aside after the accident. State Police eventually charged Koistinen with manslaughter in connection with Dang's death.

Koistinen has asked the arbitration board to reinstate him as a Windsor Locks police officer until the town can give him a proper hearing. He is also asking for at least $50,000 in back pay.