The "gotnews.com" site appears to be complete crap. However, the ABC News report you've linked is also crap.

It says unnamed "officials," think Santiago was deterred because of heavy New Years Eve police presence in New York City, in the absence of any actual evidence to support that supposition. It says that he was staying in the Anchorage hostel as a monthly resident when this story makes it clear he was paying $30 a night.

It says "agents," implying agents of the FBI, gave him his gun back, when that obviously wasn't the case.

Two of the more scary parts of this is that he was identified as being nuts in Puerto Rico, years ago, and his gun was taken away by police, only to have it given back there, as happened in Anchorage. Also, thanks to the NRA, its is quite difficult for the police to take guns away from psychotic people in many jurisdictions, especially Alaska. Tony Knowles vetoed a bill to restrict gun ownership by mentally ill persons in 1999. NRA supporters overrode him.