A Dearborn Heights man accused of killing his two children and two stepchildren in September today agreed to plead guilty to four counts of second-degree murder in the case.

Gregory Green, 50, faced charges in connection with the deaths of Chadney Allen, 19, Kara Allen, 17, Koi Green, 5 and Kaleigh Green, 4.

Green also agreed to plead guilty to torture, assault with intent to do great bodily harm less than murder and felony firearm.

He said he shot his two stepchildren in front of their mother and killed his two daughters by carbon monoxide poison.

He was found competent to stand trial following an evaluation by a doctor from the Center for Forensic Psychiatry. He last appeared in 20th District Court in October, where the children’s mother, Faith Harris-Green, sat in the courtroom with a black veil covering her face.

According to officials, Green tied Harris-Green with duct tape and zip ties, slashed her face with a box cutter, shot her in the foot and fatally shot her teenage children in front of her. The other two kids died from carbon monoxide poisoning, the Wayne County Medical Examiner’s Office ruled.

In addition to the first-degree murder charges, Green faces six felony counts in connection with the events that took place at the family's Dearborn Heights home in the 4400 block of Hipp, including torture and felonious assault.

The killings happened 25 years after Green murdered his then-wife Tonya Green, who was seven months pregnant. Court records show Green stabbed her 10 times with a steak knife, killing her and her unborn child.

He pleaded no contest to second-degree murder, served 16 years in prison and was paroled in 2008.

After the children’s deaths, Green's attorney, Charles Longstreet II, filed a notice of intent to assert the insanity defense.

Contact: Elisha Anderson: eanderson@freepress.com. Follow her on Twitter @elishaanderson.