NEW YORK AP - Investigators are piecing together more details about how a former high school football player who blamed the game for his mental health problems carried out a deadly attack on an office building that is home to the NFL.
Shane Tamura killed four people on Monday before killing himself, spraying the skyscraper's lobby with bullets and then continuing his rampage on the 33rd floor, authorities said.
Inside his wallet, a handwritten note claimed he had chronic traumatic encephalopathy, known at CTE, and accused the NFL of hiding the dangers of brain injuries linked to contact sports, investigators said.
Detectives were still working to unravel more details about the 27-year-old's background and motivations.
They planned to question a man who supplied gun parts for the AR-15-style rifle used in the attack, including the weapon's lower receiver, Police Commissioner Jessica Tisch said in a video statement.