The mayor of New York says Shane Devon Tamura may have been targeting the headquarters of the NFL when he opened fire at a skyscraper in midtown Manhattan. A three page suicide note found in Tamura’s wallet and reviewed by NBC News contains several references to the degenerative brain disease CTE,

Four people were killed, including an NYPD officer, and a fifth person was injured in a mass shooting at a Manhattan office building on Monday. Police say the suspect had a history of mental illness.