BUFFALO, N.Y. - The white gunman accused of committing a racist massacre at a Buffalo supermarket made threatening comments that brought police to his high school last spring, but he was never charged with a crime and had no further contact with law enforcement after his release from a hospital, officials said.The revelation raised questions about whether his encounter with police and the mental health system was yet another missed opportunity to put a potential mass shooter under closer law enforcement scrutiny, get him help, or make sure he didn’t have access to deadly firearms.Authorities said Sunday that they were investigating the attack on predominantly Black shoppers and workers at the Tops Friendly Market as a potential federal hate crime or act of domestic terrorism.Payton Gendron, 18, traveled about 200 miles (320 kilometers) from his home in Conklin, New York, to Buffalo to commit the attack, police said.BUFFALO, NEW YORK - MAY 15: Police and FBI agents continue their investigation of the shooting at Tops Market on May 15, 2022, in Buffalo, New York. (Photo by Scott Olson/Getty Images) Federal authorities were still working to confirm the authenticity of a racist 180-page document, purportedly written by Gendron, that said the assault was intended to terrorize all non-white, non-Christian people and get them to leave the country.RELATED: Feds interview deadly supermarket shooting suspect's parentsLaw enforcement officials revealed Sunday that New York State Police troopers had been called to Gendron's high school last June, for a report that Gendron, then 17, had made threatening statements.Gendron threatened to carry out a shooting at Susquehanna Valley High School, in Conklin, New York, around the time of.