Buffalo shooting: gunman allegedly did reconnaissance of area before rampage

Details show plotting had likely been in development for months, while signs of trouble had surrounded shooter for some time

As Buffalo, New York, mourns the victims of a mass shooting at a supermarket Saturday that left 10 dead and three wounded, details are emerging about the shooter's movements before the attack and how the devastating racist attack unfolded.

The 18-year-old shooter, who is a self-confessed white supremacist, shot 11 Black and two white victims in a racially motivated hate crime" authorities said. It plunged the mostly Black Buffalo East Side neighborhood into grief and shock.

Wires contributed to this report