Different SWAT tactics

Bizarre police styles in recent incidents.

Related to this week's mass-shooting at the Navy Yard in Washington D.C. that killed 12 people:

Sep 18, 2013 - Atlantic Wire - Report: Assault Team Ordered to Stand Down During Navy Yard Shooting

A tactical unit of heavily-armed Capitol Police officers was near the scene of the Washington Navy Yard shooting as it happened, ready and capable of stepping in. But according to multiple sources speaking to the BBC, that unit was ordered to stand down and leave the scene, instead of helping the Municipal Police Department take down the shooter.

The officers, part of a four-man Containment and Emergency Response Team responsible for guarding the nearby Capitol, were "wearing full tactical gear and armed with HK-416 assault weapons" when they arrived near the scene of the then active mass shooting on Monday morning, according to the BBC. Here's what allegedly happened next:

According to a Capitol Police source, an officer with the Metropolitan Police Department (MPD), Washington DC's main municipal force, told the Capitol Cert officers they were the only police on the site equipped with long guns and requested their assistance in searching for the gunman.

When the Capitol Police team radioed in to their superiors, they were told by a watch commander to leave the scene, the BBC was told.

The Capitol Police are pulling radio logs from Monday morning to investigate the incident, according to a spokesperson for the agency, who added that the department provided "mutual support and assistance" in the aftermath of the shooting.

The Sep 18, 2013 - BBC - Navy Yard: Swat team 'stood down' at mass shooting scene

One of the first teams of heavily armed police to respond to Monday's shooting in Washington DC was ordered to stand down by superiors, the BBC can reveal.

A tactical response team of the Capitol Police, a force that guards the US Capitol complex, was told to leave the scene by a supervisor instead of aiding municipal officers.

The Capitol Police department has launched a review into the matter.

Aaron Alexis, 34, killed 12 people at the Washington Navy Yard.

"I don't think it's a far stretch to say that some lives may have been saved if we were allowed to intervene," a Capitol Police source familiar with the incident told the BBC.