NYC gunman who killed 4, including NYPD officer, claimed CTE in suicide note

Let's just go back a little bit and walk us through what exactly happened last night. Looks like the man double parked his car and kind of walked in just holding out in the open that semi-automatic rifle. >> Yeah, an incredible site here in New York City because obviously people don't open carry assault rifles around this city and you're used to seeing them uh on police officers.So, we do see him on a surveillance camera walking in. That's the camera there that captures captures him walking into this buildi ...