NYPD: Suspect in NYC shooting has 'documented mental health history'

A gunman who killed a NYPD officer and three others in a Manhattan high-rise building last night left behind a note that referenced the NFL and CTE, according to sources. MSNBC Investigative Correspondent Marc Santia reports from outside the building. Former NYPD Detective Tom Verni and independent political strategist Reed Galen join Chris Jansing to discuss the latest updates. For more context and news coverage of the most important stories of our day click here: https://www.msnbc.com/ » Subscribe to MSNBC:    / msnbc   » Subscribe to MSNBC on TikTok   / msnbc   » Subscribe to MSNBC on Instagram   / msnbc   Download our new MSNBC app for the latest breaking news and daily headlines at a glance: https://www.msnbc.com/information/dow... Follow MSNBC Show Blogs MaddowBlog: https://www.msnbc.com/maddowblog MSNBC delivers breaking news, in-depth analysis of political headlines, commentary and informed perspectives. Find video clips and segments from The Rachel Maddow Show, The Briefing with Jen Psaki, Morning Joe, The Beat, Deadline: White House, The Weeknight, All In, The Last Word, The 11th Hour, and more. Connect with MSNBC Online Visit msnbc.com: https://www.msnbc.com/ Subscribe to the MSNBC Daily Newsletter: https://link.msnbc.com/join/5ck/msnbc... #NewYorkCity #Crime #Shooting