The 18-year-old gunman accused of killing 10 at a grocery store in Buffalo, N.Y., had undergone a mental health evaluation by New York state police after making a school shooting threat last year, authorities said.
"The state police responded. They investigated. They interviewed the subject. And they felt at the time it was appropriate to have that individual brought in for a mental health evaluation," said Buffalo police commissioner Joseph Gramaglia at a press conference Sunday.
