New York native Omar Mateen has been identified as the gunman behind the horrific Florida nightclub shooting that left 50 dead
New York native Omar Mateen has been identified as the gunman behind the horrific Florida nightclub shooting that left 50 dead. Former ATF agent Matt Horace joins CBSN to discuss how Mateen got possession of heavy firearms, and what authorities are doing to monitor gun use in the U.S.
