SOUTH BRONX, Bronx (WABC) -- A doctor's apartment is now the focus of an investigation into the shooting rampage at a New York City hospital last week.
NYPD has sealed Dr. Henry Bello's apartment, saying no one should enter without authorization.
Inside the apartment, police found the box for the semi-automatic rifle Bello used in his shooting spree at Bronx-Lebanon Hospital. That box allowed police to trace the weapon to a gun store near Albany.
But how did Bello who hadn't worked at the hospital in more than two years get by security with a huge gun? Even wearing his old doctor's coat, Bello should have been stopped by security which requires visitors to get passes and all staff to show hospital ID.
"As far as employees, each of them has On and ID, similar to the one I have and are not permitted to enter unless that ID is shown," Bronx-Lebanon Hospital spokesman Errol Schneer said.
PHOTOS: Images from the scene
It raises the question, did the hospital fail to get Bello's ID badge back when they terminated him in 2015?
"We don't know, that's something we're investigating, even more importantly, the police of New York are investigating," Schneer said.
Related: Father of Bronx Lebanon Hospital shooting victim speaks out
But one source who works at Bronx-Lebanon said, "There's hardly ever a security check for doctors. A white coat gains one access to all hospital areas, no questions asked."
Another key security question again being asked, should hospital guards be armed.
"How many people have to be shot or stabbed before we decide to arm those tasked with protecting our hospitals?" Security expert Ed Gavin said.
Doctor's apartment searched for clues after Bronx-Lebanon Hospital shooting
BRONX HOSPITAL SHOOTING