Flaws in system gave Washington gunman security clearance

Gaps in how the US military conducts background checks enabled the gunman in the Washington Navy Yard rampage to obtain a high-level security clearance and gain access to protected installations, despite a history of disciplinary problems in the navy and run-ins with police.

It is still unclear how 34-year-old former navy reservist Aaron Alexis was allowed to slip through a supposedly thorough examination of his conduct, some of which was easily found by simple internet searches.

In the wake of the deadly attack, President Barack Obama yesterday ordered a sweeping review of all federal agencies' practices for allowing access to civilian employees and contractors who work for the government.

Alexis' employer at the Navy Yard, a federal subcontractor based in Fort Lauderdale, Florida, called The Experts, said the Defence Department had confirmed his "secret" security clearance twice in the past year, even though he had been arrested three times between 2004 and 2010, twice for gun incidents.

"The latest background check and security clearance information were in late June of 2013 and revealed no issues other than one minor traffic violation," The Experts said.

But police records show that Alexis was arrested in 2004 after he shot out the tyres of a car near his Seattle home; arrested in 2008 for disorderly conduct near Atlanta; and arrested in 2010 in Fort Worth, Texas, after his gun was fired into his ceiling and through a neighbour's floor. He was not prosecuted in any incident.