• A senior Navy officer told CNN's Jake Tapper that Navy officials knew about Alexis' 2004 arrest for shooting out the tires of a car, but they decided to grant him security clearance anyway in 2007.
• The officer says the investigators knew of the incident and interviewed Alexis but decided it did not preclude granting the clearance. He "should have been screened out early in his enlistment," one expert says.
• Mert Miller, an Office of Personnel Management official, said the agency conducted a "background security clearance investigation for Aaron Alexis in 2007, and the Department of Defense adjudicated his file and granted his security clearance in 2008."
• The agency is working with the Office of Management and Budget and the director of national intelligence "to review the oversight, nature and implementation of security and suitability standards for federal employees and contractors," Miller said Tuesday.
• "In general, background security clearance investigations include information about an individual's criminal history, including criminal records, and that information would be passed on to the adjudicating agency," said Miller, associate director of the Office of Personnel Management's Federal Investigative Services.
• Some question how Alexis, who had some run-ins with the law, was allowed access to a military installation. The Navy ordered a review of security and access controls at Navy installations around the world. An initial review would be completed within two weeks, Adm. Jonathan Greenert, the Navy chief of operations, told a congressional committee Wednesday.
• Sen. Susan Collins, R-Maine, told "New Day" on Wednesday that "serious questions" need to be posed "about whether contractors are taking shortcuts that have led to people with criminal records, with serious mental illness, or who are authorized unsuited for security clearances, nevertheless being granted them, and for a period as long as five to 10 years."
• Collins said it is "simply inexcusable" for the Navy "to have received a call that indicates that an individual with unfettered access to a Navy base clearly is suffering from a serious mental illness and not immediately revoke his security clearance until they can assure that he does not pose a threat to others and himself."
• "It's incumbent," Collins said, "to work together to get to the bottom of this crisis and ensure that it is fixed."
"One step that can be taken immediately is ensuring that criminal databases and the terrorist watch lists are always consulted, and that there's some sort of continuous monitoring that would pick up problems rather than waiting as long as five or 10 years to review security clearances."
Who are the victims?
• They were civilians and contractors, just starting their day at a massive military compound that's normally a bastion of safety. But for reasons that may never be known, Alexis, a former Navy reservist, cut their lives short.
• The family of Sylvia R. Frasier, one of the 12 people killed in the Washington Navy Yard shooting, said in a statement that she had been "a friend to everyone she met and a stranger to no one." "The only hurt she caused us was the void that was left when she was snatched up prematurely and gone too soon. She will be sorely missed."