Newtown Killer himself died within 5 minutes of the attack starting

Note that it took 20 minutes for the police to even arrive outside the school after the first 911 call.  The problem is that someone with a gun needs to be able to arrive on the scene much more quickly than is currently possible.  From Fox News:

An arsenal of weapons including guns, a gun safe with shotgun shells, a bayonet and several swords were found in the home of the gunman who carried out the Newtown school shooting, according to search warrants released Thursday. 

Adam Lanza killed 26 people inside Sandy Hook Elementary School and took his own life within five minutes of shooting his way into the building, State's Attorney Stephen J. Sedensky III said in a statement accompanying the release of the warrants in the Dec. 14 massacre. 

The extensive inventory of the evidence seized from Lanza's home and the car he drove to carry out the massacre provided glimpses into the world of the reclusive gunman. 

Prosecutors until now had made few details available, despite pressure to do so from the governor, who criticized leaks to the press and lawmakers who clamored for more details as they craft legislation on mental health and gun control. . . . 

Sedensky says Lanza killed all 26 victims inside Sandy Hook Elementary School with a Bushmaster .223-caliber rifle before taking his own life with a Glock 10 mm handgun. He says Lanza had another loaded handgun with him inside the school as well as three, 30-round magazines for the Bushmaster. . . .