The US Navy said Monday it is pushing for more rigorous background checks after a review showed gaps in the case of a former sailor who went on a shooting rampage last week.

Officials acknowledged that the Navy Yard shooter, Aaron Alexis, did not disclose an arrest or a number of debts when he applied for a security clearance when he joined the Navy as a reservist in 2007. But he was given the secret clearance anyway.

And a background check by a government agency handed over to the Navy failed to mention that Alexis had shot out the tires of someone else's car during an argument over parking in Seattle.

The Office of Personnel and Management instead told the Navy that Alexis had retaliated in the 2004 dispute by "deflating" the tires of another person's car.

The account given to the Navy was based on an interview with Alexis by investigators "regarding the subject's unadmitted criminal offense and financial issues," according to a report by the Office of Personnel Management.

The Navy did not learn of the 2004 shooting, which had been detailed in a Seattle police report that was apparently never shared with background investigators, until after last week's rampage, officials said.

The account raised fresh questions about how security clearances are handled and how police departments cooperate with those investigations.

The details of how military authorities had lacked a full picture of the shooter emerged in a review of the case conducted by naval officials in recent days.

As a result, Navy Secretary Ray Mabus has recommended to Defense Secretary Chuck Hagel that "any available police documents" be examined in future background checks for security clearances, according to a memo released to reporters.

Mabus also recommended improving sailor evaluations by assigning more senior officers to carry them out.

Alexis, 34, was killed after he gunned down 12 people at the Navy Yard in the heart of Washington on September 16. He had left the Navy in 2011 and become a subcontractor for a firm working on a project for Hewlett-Packard.

Alexis told investigators for his security clearance that he did not mention his arrest in Seattle, because he had been told the incident would not appear on his record as charges were never pressed.