A 27-year-old Chinese immigrant was sentenced on Tuesday to 125 years in prison for killing his cousin's wife and children with a meat cleaver at their Brooklyn home, prosecutors said.

Mingdong Chen was sentenced after pleading guilty earlier this month to butchering the woman and her four young children at their Sunset Park apartment on Oct. 27, 2013. Chen had been staying with the his cousin and his family for about two weeks before the attack.

"This defendant's vicious and sadistic attack makes him completely unfit to remain in society and he will now spend the rest of his life behind bars," Brooklyn District Attorney Ken Thompson said in a statement. "While we will never know what drove him to commit these murders, I hope that this sentence will offer this grieving family some measure of comfort."

On Oct. 27, 2013, 37-year-old Qiao Zhen Li called her mother-in-law in China to say her cousin had a knife and was threatening them, according to prosecutors. The four children -- Linda Zhuo, 9; Amy Zhuo, 7; Kevin Zhuo, 5; and William Zhuo, 1 -- could be heard crying in the background.

The mother-in-law then called on other relatives in Brooklyn to check on them, but when they arrived they found Chen covered in blood and Li and her children slaughtered.

The five victims had died from multiple wounds to the neck and head.

Chen was charged with three counts of second-degree murder and two counts of first-degree manslaughter.

Speaking in Mandarin, Chen then confessed to killing all five killings.