DEARBORN HEIGHTS (WWJ/AP) – An ex-convict has pleaded guilty to second-degree murder in the slayings of his two young children and two stepchildren at his Dearborn Heights home.

Gregory Green also pleaded guilty Wednesday to torture and assault in an attack on his wife.

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Green’s biological children, 5-year-old Koi Green and 4-year-old Kaleigh Green, died from carbon monoxide poisoning in September in the Dearborn Heights home.

His stepchildren — 19-year-old Chadney Allen and 17-year-old Kara Allen — were fatally shot in front of their mother, Faith Green. She also was the mother of Koi and Kaleigh.

According to prosecutors, Green called 911 around 1:15 a.m. on Sept. 28 and admitted to killing his family. When police arrived at the home — in the 4400 block of Hipp, near Pelham and Annapolis roads — Gregory Green was waiting on the porch and was immediately taken into custody.

After the arrest, police entered the home and discovered Faith Green in the basement, bound with duct tape and zip ties. It is alleged that Gregory Green bound his wife, cut her face with a box cutter and shot her foot. Prosecutors say he then shot his teenage stepchildren in front of his wife, multiple times, execution style. Both were pronounced dead at the scene.

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Upstairs, police discovered the bodies of Gregory Green’s biological children tucked into their beds. It is alleged that he poisoned the two younger children with carbon monoxide — duct tape was observed on the muffler of a car in the garage and a plastic tube was attached to the car — and then moved their bodies back inside the home. The children were pronounced dead at a local hospital.

Faith Green, who prosecutors said was slashed with a box cutter and shot in the foot, was rushed to the hospital and survived. She’d previously filed for divorce.

Gregory Green was released from prison in 2008 after serving 16 years for killing his first wife, who was pregnant.

Sentencing in the case is scheduled for Wednesday, March 1.

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