The gunman suspected of targeting the National Football League headquarters in New York, killing four, was a former football player at two Southern California high schools.

Police have identified the man who they say entered a Midtown Manhattan office building wearing body armor and opened fire, killing four people with a high-powered rifle, as Shane Devon Tamura.

Adams told reporters that investigators believe Shane Tamura of Las Vegas entered the building with the intent to reach the NFL 's offices but accessed the wrong set of elevator banks. "He seemed to have blamed the NFL ," Adams said. "The NFL headquarters was located in the building, and he mistakenly went up the wrong elevator bank."