"They didn't give me any red flags," a devastated Chadney Allen Sr. says of his only children who, police say, were murdered by their stepfather.
Allen tells 7 Action News that he had no idea his ex-wife's husband, Gregory Green, was convicted in the 1991 killing of his first wife, Latonya (Tonya) Green who was pregnant with Green's child at the time.
Tonya had two young children at the time. One was able to hide in a closet, but they were not physically harmed.
On Wednesday, Dearborn Heights Police say Gregory Green killed his two teenage stepchildren, Kara Allen, 17, and Chadney Allen Jr., 19, and his biological daughters, 5-year-old Koi and 4-year-old Kaliegh.
Police say Green shot the teens in front of their mother, Faith Green, to make her suffer because she wanted a divorce and he believed she was cheating on him.
Faith had been bound with duct tape and zip ties in the basement of their home in Dearborn Heights and forced to watch her children being killed.
Gregory Green allegedly killed the little girls by placing them in a car and rigging the exhaust to leak back into the vehicle.
Relatives of Gregory Green claim Faith knew he had spent time in prison for the murder of his first wife.
Chadney Allen Sr. says he only met Gregory Green one time and never knew about his criminal past.
In 1991, while being prosecuted in the murder of his first wife Tonya, court records show Green attempted to use insanity as a defense.
On July 14, 1991, Gregory Green called police and, when officers arrived, he opened the door and told them "I stabbed her. She's in the kitchen."
Moments after officers found Tonya's body in the kitchen, Green told them where to find the knife. He had placed it on the refrigerator.
According to the medical examiner's report, Tonya suffered stab wounds to her left cheek, neck, chest and back. She was 30 weeks pregnant at the time of her murder.
One of Tonya Green's relatives says they were devastated when he received a sentence of 15 to 20 years in prison.
Gregory Green was released after serving 16 years in prison.
"I don't believe Gregory is a threat to society," Gregory Green's mother, Tommie Lee Green, wrote a judge in 1992 asking for leniency. "I don't believe a long sentence will make him any better because he has suffered already and he will continue to suffer the rest of his life."
Tommie Lee Green died several years ago, never knowing her son would be accused in the killing four children, including two more of his own, and injuring another wife by cutting her face with a box cutter and shooting her in the foot.