Twisted Gregory Green pleaded guilty to killing his two children, aged four and five, by poisoning them with carbon monoxide, then shooting his older step children, age 17 and 19, dead.
A court heard how he altered the exhaust system of his car before putting his young children Kaleigh, four, and Koi, five, inside and poisoning them to death.
Green, 50, then forced her to watch while he shot and killed his older stepchildren Kara Allen, 17, and Chadney Allen, 19, at their home in Dearborn Heights, Detroit last September.
He calmly called 911 after the murders and waited in the driveway until police arrived.
The heartbroken mum blasted her now ex-husband in court telling him he was the “devil in disguise” and that he would “burn in hell”, The Detroit News reported.
She paid tribute to her four children before telling the courtroom:
“I can still feel the zip ties around my wrists.
“Some days I wish I died. There’s a hole in my heart and soul that will never be repaired.”
Green, 50, told the courtroom “Only God can judge me” before his sentence was handed out.
Wayne County Court Judge Dana Hathaway sentenced him to 47 to 102 years in prison, telling Green the case was “by far the worst” she’d ever seen.
She added: “Your actions are inconceivable.”