Buffalo gunman pleads guilty over racist supermarket massacre

(Matt Rourke/AP)

The gunman who killed 10 black shoppers and workers at a Buffalo supermarket has pleaded guilty to murder and hate-motivated terrorism charges, guaranteeing that he will spend the rest of his life in prison.

Payton Gendron, 19, entered the plea on Monday in a courthouse two miles from the grocery store where he used a semi-automatic rifle and body armour to carry out a racist assault he hoped would help preserve white power in the US.