Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
The latest on the crisis in Ukraine, plus why a 700-page book on economic theory is a best seller.
By CNN's Chief Washington Correspondent Jake Tapper
Navy officers were aware that in 2004 Aaron Alexis was arrested for shooting out the tires of a car in a black-out fueled by anger, and yet they admitted him into the Navy and granted him security clearance in 2007 anyway, a senior Naval officer told CNN.
"It appears as if investigators were aware of the incident, interviewed him and were satisfied that it did not preclude granting the clearance," the officer said.
Alexis, who on Monday killed twelve innocent people at the Washington Navy Yard, was a military contractor who used a valid identification to gain access to the secured yard, law enforcement officials said Tuesday.
But lawmakers and many in the media are now asking how Alexis was able to obtain that clearance, given his previous run-ins with the law, some involving guns, as well his checkered past in the Navy and a history of mental illness.
Alexis "should have been screened out early on in his enlistment," said one expert on Navy processes, who asked not to be identified. "The Navy and the various entities responsible for his adjudication were either unwilling or worse unable to determine he was unfit for service in the United States Navy."
At around 8 in the morning on May 6, 2004, Alexis used his Glock and shot out two of the tires of a 1986 Honda Accord near a Seattle, Washington, home where Alexis was residing. He was ultimately arrested and charged with "malicious mischief." Alexis said that the owners of the car "had disrespected him" and that, he claimed, led "to what Alexis described as a 'black-out' fueled by anger," according to the police report.
Before obtaining clearance as a contractor, Alexis would have theoretically been investigated by the Office of Personnel Management and ultimately granted clearance by "DONCAF" - the Department of the Navy's Central Adjudication Facility, in Fort Meade. An official at DONCAF refused to comment, referring CNN to the Pentagon. Rear Admiral John Kirby, chief of information for the U.S. Navy, told CNN he couldn't speak for DONCAF or its process, but Alexis "passed a routine security clearance back in 2007 when he enlisted. It was good for 10 years."
As a reservist Alexis was exempted from the periodic reinvestigation of clearance that active duty officers go through every 4.5 years, or the polygraphs they go through every 2.5 years.
Kirby said, "We're doing the forensics now to better understand if and how that clearance was reviewed. If we need to account for missed flags, we will. While not a stellar sailor, nothing Alexis did gave us an indication that he was capable of this brutal level of violence against people."