A father who poisoned his two young daughters and shot dead his teenage stepchildren has been jailed for nearly 50 years.

Gregory Green, who served 16 years for murdering his first wife, left his second wife fighting for her life after the attack.

But as the 50-year-old, from Detroit, Michigan, was told he would be 97 before he is eligible for parole, the mother of the four murdered girls told him she hoped he will "burn in hell".

"I'm not happy, I'm not satisfied with the outcome, there is no punishment that fits the crime, not even torture and death would be justice," Faith Green told the court.

"Your justice will come when you burn in hell for all eternity for murdering four innocent children, all because you are insecure as a man.

She added: "You are a con artist, you are a monster, you are a devil in disguise, you are now forever exposed."

Green called police in September to report the deaths of his daughters, aged four and five, and stepchildren, aged 17 and 19, at the family home.

Faith Green, who had filed for divorce at the time, was bound, cut in the face with a box cutter and forced to watch as her teenage children - Kara Allen and Chadney J Allen - were shot in front of her, police said.

Their two daughters, Kayleigh Green and Koi Green, were asphyxiated through carbon monoxide poisoning.

Faith Green said she sometimes wakes up "screaming and sweating", thinking she can save her children.

A GoFundMe page set up by her sister has raised more than $50,000 dollars.

Green told the court: "I just want to say first of all, it is in God's hands and only he can judge and you know I do regret and I am sorry for what has happened.

"All I ever wanted was a God fearing couple to help me, that would support me and be faithful, no matter what and would dedicate to the whole family.

"You know that put aside, you know I have to be humble, very humble because God knows the heart, he knows how regretful and sorry I am and even now after all this, he still has a plan."

Green married his wife Faith in 2010, two years after he left prison on his fifth request for parole.

He had pleaded no contest to killing his first wife, who was pregnant, in 1991.