Buffalo gunman pleads guilty to all charges of race-motived domestic terrorism in supermarket attack

The 19-year-old white gunman who killed 10 black shoppers and workers at a Buffalo supermarket in May pleaded guilty Monday to murder and hate-motivated terrorism charges.

Payton Grendon's guilty plea guarantees he will spend the rest of his life behind bars, the Associated Press reported. 

Grendon pleaded guilty to all state charges including murder, murder as a hate crime and domestic terrorism motivated by hate, which brings an automatic life sentence without parole. He also pleaded guilty to wounding three others who survived the attack.

He previously pleaded not guilty to federal hate crimes charges, and the Justice Department has not said whether it will seek the death penalty for it.