DEARBORN HEIGHTS (WWJ/AP) – Records show a man suspected of killing two young children and two teenagers at his home served 16 years in prison for second-degree murder.

Gregory V. Green was released from prison in 2008 after serving 16 years for second-degree murder. He had pleaded no contest in Wayne County court.

Corrections Department spokesman Chris Gautz says Green was charged with fatally stabbing his pregnant wife in 1991.

Wednesday morning a call came in to police from a man claiming to have killed his family.

Inside the home, investigators found a 4-year-old Kaliegh Green and 6-year-old Koi Green dead in their beds, a 17-year-old girl and 19-year-old boy dead in the basement, and the suspect’s wife suffering from gunshot and stab wounds.

The wife, identified as Faith Green, was rushed to a local hospital and last reported in fair condition.

Lt. Michael Krause said it appears the younger children — identified as Kaleigh and Koi — were asphyxiated in the suspect’s vehicle; a hose had been hooked to the exhaust and was routed into the car. After the girls succumbed to carbon monoxide poisoning, the suspect allegedly moved their bodies back inside the home and tucked them into bed. As for the older children — identified as Kara Allen and Chadney Allen — officials say both were shot execution style.

The suspect is said to be the biological father of the two youngest children; Green is the biological mother of the two older children.

Green was arrested and is currently being held at the Dearborn Heights Police Department and is expected to be arraigned by Thursday.

An investigation is ongoing.

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