The gunman who shot five people, killing four, in a Midtown Manhattan office tower home to Blackstone and the National Football League was identified late Monday as 27-year-old Shane Devon Tamura. He reportedly had grievances with the NFL but ended up on the wrong floor during the attack, ultimately killing himself on Rudin Management's floor. 

Authorities say Tamura drove from Las Vegas to 345 Park Ave. in Manhattan. According to a CNN source, a suicide note was found in Tamura's pocket expressing Chronic Traumatic Encephalopathy (CTE)-related struggles. One victim remains in critical condition, and an NFL employee was seriously injured. 

Here's what CNN sources are saying:

Latest headlines (courtesy of CNN): 

A lot can be inferred from the setup of a rifle for a specific operation. Notably, Tamura used a knockoff Trijicon ACOG (Advanced Combat Optical Gunsight), which is designed for effective engagement out to 800 meters. Unless the shooter had an offset red dot sight (e.g., mounted at 45 degrees) for rapid target acquisition in close quarters, the optic choice suggests he wasn’t equipped for close-range combat—though that has not been confirmed.

Office workers at 345 Park Ave barricaded themselves to prevent the shooter from entering their floor. 

The shooter was found dead on the 33rd floor, which is Rudin Management's floor. 

Alleged interview of Tamura when he was a football player in high school. 

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