CERT tactical response teams were located a few blocks from the Navy Yard and so arrived on the scene within minutes, but the official inquiry has since tried to whitewash this fact by claiming they were called away after being "stuck in traffic"...
Specially trained unit did not respond to shooting which killed 12 in part due to concerns about threat to US Capitol

A specially trained tactical Capitol police squad was recalled from responding to the Washington navy yard shooting in part because of concerns about possible threats to the US Capitol, according to a report released on Friday. The report calls the decision reasonable.

The two-page document says the unit, which responds to emergencies like the mass shooting on 16 September, became stuck in traffic and was unable to reach the command post during the event. A supervisor recalled the four-member unit because of concerns about possible threats at the US Capitol and because there were no further requests for help, the report states.

A summary of the findings was released by the Capitol police board. The investigation was launched days after the shooting, amid reports that a Capitol police supervisor had told the Containment and Emergency Response (CERT) Team to stand down, instead of responding to the shooting.

Senate sergeant at arms Terrance Gainer, who serves on the Capitol police board, said the decision to recall the unit made sense in light of the fact that the officers had not even reached the building and were not prepared to go in.

"I think speculating on whether anybody including the CERT officers could have made a difference is actually unfair," Gainer said, later adding, "Over my 43 years [in law enforcement], I always question whether I could have done something different to prevent a crime."

The gunman, Aaron Alexis, a former navy reservist and government contractor, killed 12 people inside the building where he worked before dying in a police shootout. The FBI has said he was suffering from delusions.

Source: Associated Press