Security guard overpowers gunman who opened fire in methadone clinic

01:03CCTV footage captures the moment a security guard overpowers a gunman who walked into a methadone clinic and fired shots into the wall. The man can be seen entering the building in Buffalo, New York, with an AR-15, causing panic as he opens fire. While staff run for cover, the guard grabs the gunman and manages to force him back outside. After another two shots are fired, four people – including the guard – subdue the man and pull the weapon away from him in the street. Click here to sign up for our newsletters.