Chinese-born Mingdong Chen has just been handed a 125-year prison sentence for butchering five of his relatives, including four children who were less than 10 years old.

Chen pleaded guilty to murder and manslaughter charges in a plea deal that would spare him the death penalty, according to a Associated Press report.

He was given three terms of 25 years to life for murder, and two additional terms of 25 years to life on the manslaughter charges.

Brooklyn District Attorney Ken Thompson called it a “vicious and sadistic attack makes him completely unfit to remain in society, and he will now spend the rest of his life behind bars,” according to the report.

Chen, 27, killed 37-year-old Qiao Zhen Li, his cousin’s wife, as well as her children, who were 9, 7, 5, and 1 years old. The incident happened back in October 2013.

Chen was reportedly upset about being fired from restaurant jobs and was jealous of the success of his relatives. Chen began threatening Li with a knife on that fateful night, prompting Li to called her mother-in-law in China, who subsequently contacted relatives in New York after hearing the crying of the children.

But when relatives and authorities arrived, it was too late: Chen had cut the throats of his victims and was covered in blood. Still, authorities even now aren’t exactly sure why he did it.