An 18-year-old who allegedly wrote a White supremacist manifesto traveled from hours away to a predominantly Black neighborhood in Buffalo, New York, and opened fire in a supermarket Saturday, killing 10 people and wounding three, authorities said.

Eleven of the people who were shot at the Tops Friendly Markets store were Black, and authorities say they believe the mass shooting was racially motivated. The victims included a former Buffalo police lieutenant working as a security guard and the mother of Buffalo’s retired fire commissioner, Mayor Byron Brown said.

The shooting was a “straight up racially motivated hate crime from somebody outside of our community,” Erie County Sheriff John C. Garcia said Saturday. “This was pure evil.”