Police rushing to the scene of last year's Navy Yard shooting in Washington D.C. were hampered in their attempts to help by numerous delaying hurdles such as being locked out of room with live surveillance video, an internal report said.
The Metropolitan Police Department's review of its response to last September's shooting said better access to camera footage - in a room locked by a security guard - would have helped first responders as they pursued gunman Aaron Alexis, who killed 12 people before being slain by police.
"The footage may have ... allowed police to quickly identify the shooter, ascertain his movements, and help in determining whether others may have been involved," said the review released on Friday.
Officers were further delayed during the frenetic multi-agency response by trouble getting through locked gates, navigating the sprawling complex and finding Building 197, where most of the killing occurred, and by protocol-following Navy Yard witnesses dialing an emergency operations center rather than the civilian-used 911, the report said.
The 83-page post-mortem sought to summarize the Metropolitan Police Department's tactical response to the rampage in relation to other agencies working the frenetic scene, including news media, which for a time posted to Twitter developments overheard on police scanner frequencies.
It comes in the wake of a series of mass shootings in public places across the U.S., including military installations, and a broader national debate on the extent of gun control regulations.
"Officers relied upon their training, experience, and instincts to run into an unfamiliar and massive building, towards the gunshots and certain danger, in order to stop the gunman from taking more lives," the report's preamble said.
The Police Department's conclusions follow other reviews of the incident published earlier this year, including one that said the tragedy might have been averted had authorities not "missed opportunities for intervention."
Defense Secretary Chuck Hagel ordered steps to improve Pentagon security after the reviews found the shooting could have been averted if concerns about the gunman's mental health had been properly handled.
Alexis, a 34-year-old former sailor with a prior record of firearms complaints, had reported hearing voices and suffering from insomnia in the weeks before he opened fire at the base with a sawed-off shotgun.
He had been working at the facility as an information technology subcontractor, using access he gained in part because of his 10-year security clearance issued in 2008.
(Reporting by Eric M. Johnson; Editing by Sophie Walker)