Shooter kills 4, Including NYPD officer, in NYC office building

The Brief

Five people were shot, and four died, including an NYPD officer, in a Manhattan office tower on Monday before the shooter took his own life.

The shooter, Shane Tamura, a California native from Las Vegas with a history of mental illness, targeted the building, believing the NFL was responsible for his problems.

Authorities are investigating Tamura's motive and background, including his claims of CTE despite never playing in the NFL.

NEW YORK, NY - New York police are trying to make sense of the senseless act of violence on Monday in a Manhattan office tower where five people were shot, with four dying before the shooter took his own life.

What we know:

First, it starts with who he is: Shane Tamura, a California native who lived in Las Vegas, with a history of mental illnes