WASHINGTON — Washington Navy Yard shooter Aaron Alexis obtained a secret-level security clearance after a federal personnel report failed to mention that a 2004 arrest involved a firearm, the Navy said Monday. 
 
 A senior Navy official told reporters the service learned of the incident's violent nature only after Alexis had shot 12 people to death at the Washington Navy Yard last week and was himself fatally shot by police. 
 
 The Office of Personnel Management knew of Alexis' Seattle arrest because of a fingerprint check when he joined the Navy Reserve in 2007 and interviewed him about it, the official said. Alexis had not disclosed the offense on his security questionnaire. 
 
 Alexis said that he had an altercation with a man doing construction work near his home and that the men had been "taking retaliatory action toward each other's parked cars," according to the investigative document that the personnel office gave to the Navy. Alexis said the construction worker had put a foreign substance in Alexis' gas tank, and Alexis retaliated by "deflating the male person's tires," according to the report. 
 
 That account "reads very different from the police account of what took place that day," the senior official said. The Seattle police report says Alexis shot out the tires and was charged with malicious mischief, the official said. 
 
 Monday's disclosure revealed another in a chain of missed opportunities by the Navy and Alexis' civilian employer — a military contractor — to come to grips with his violent tendencies and apparent mental illness. Alexis had complained that he was hearing voices and being bombarded by microwaves. Because of his job, which required a security clearance, he had a valid ID card that allowed him to enter the Navy Yard. 
 
 "The summary of the Seattle incident that was provided to [the Navy] makes no reference to firearms, makes no reference to a gunshot ... makes no reference to firing into the air," the Navy official said. The Navy provided access to the briefing on condition that the official not be identified. 
 
 The personnel office said Seattle police would not provide records on the 2004 incident. The office interviewed Alexis, who did not say that a weapon was involved. The personnel office said it could not force police departments to cooperate. 
 
 The Navy cleared Alexis based on all the information it had, the senior official said, and there is no way to know "how they would have adjudicated knowing the events we know now. In a vacuum looking back, what we do know is that the events suggest very different activity." 
 
 The construction worker did not press charges and the case was dismissed, the personnel office told the Navy. 
 
 Sometimes personnel office investigations include police documents, the Navy official said, but in this case the report sent to the Navy did not. 
 
 A recent memo sent to Navy Secretary Ray Mabus from Assistant Navy Secretary Juan M. Garcia included a recommendation that all personnel office investigative reports include "any available police documents related to the subject being investigated for clearance eligibility." The recommendation has been sent to Defense Secretary Chuck Hagel. 
 
 On his security clearance form, Alexis answered "no" to questions about whether he had been charged with or convicted of a felony, and "no" to whether he had been arrested by any law enforcement official in the last seven years. The personnel report said Alexis said he did not disclose information about his 2004 arrest because the charge was dismissed and he was told by his attorney that it would be removed from his record. 
 
 Alexis was found to be eligible for the security clearance in March 2008 after the Navy reviewed the personnel investigation. The only concern was Alexis' credit history, according to a timeline released by the Navy. His clearance was valid for 10 years. 
 
 In September 2008, Alexis was arrested in DeKalb County, Ga., on suspicion of disorderly conduct and jailed for two nights, resulting in an unauthorized absence. The Navy gave Alexis an administrative punishment. 
 
 In July 2009, he was punished again for being "drunk and disorderly," according to the timeline. But there was no police involvement, and Alexis successfully appealed the punishment, which was removed from his record. 
 
 In September 2010, he was arrested in Fort Worth for discharging a firearm in his home after an altercation with a neighbor. Alexis told police the gun accidentally went off as he was cleaning it. No charges were filed. 
 
 After the Fort Worth incident, Alexis' commander began the process "to administratively separate him from the Navy," according to the timeline. But when Alexis was not charged, the matter was dropped. 
 
 Alexis left the Navy three months later with an honorable discharge. 
 
 becca.clemons@latimes.com ||||| Aaron Alexis, 34, has been identified by officials as the gunman in Monday’s shooting at the Washington Navy Yard. In 2010, Alexis was arrested by Fort Worth police after a bullet was fired through the floor of his upstairs neighbor’s apartment. He told police that his gun accidentally discharged while he was cleaning it, and no charges were pursued. 
 
 Aaron Alexis, 34, has been identified by officials as the gunman in Monday’s shooting at the Washington Navy Yard. In 2010, Alexis was arrested by Fort Worth police after a bullet was fired through the floor of his upstairs neighbor’s apartment. He told police that his gun accidentally discharged while he was cleaning it, and no charges were pursued. Fort Worth Police Department/via AFP/Getty Images 
 
 Authorities say the former Navy reservist, who had been living in Fort Worth, was the dead gunman at the Washington Navy Yard. 
 
 Authorities say the former Navy reservist, who had been living in Fort Worth, was the dead gunman at the Washington Navy Yard. 
 
 Authorities say the former Navy reservist, who had been living in Fort Worth, was the dead gunman at the Washington Navy Yard. 
 
 The military’s beleaguered background-check system failed to block Navy Yard gunman Aaron Alexis from an all-access pass to a half-dozen military installations, despite a history of arrests for shooting episodes and disorderly conduct. 
 
 Alexis, a military contractor working on a computer project, used his secret-level clearance to gain entry to the Washington Navy Yard on Monday, where officials said he gunned down a dozen people before being killed by police. 
 
 The revelations about Alexis’s troubled past — and his ability to pass the government’s security-check system — prompted multiple examinations Tuesday into how background checks are conducted and how long a security clearance can last without review. The system was already under scrutiny after leaks of classified documents by fugitive National Security Agency contractor Edward Snowden. 
 
 President Obama directed his budget office to conduct a government-wide review of security standards for contractors and employees across federal agencies. Defense Secretary Chuck Hagel also ordered a broad review into security and access to military installations worldwide. 
 
 More than 24 hours after the deadly rampage, there was still widespread confusion over how Alexis managed to escape scrutiny since being given access to classified materials and facilities five years ago. The private contractor that most recently employed him pointed the finger at the Defense Department, which defended its handling of the case. 
 
 Alexis was granted secret-level security clearance in March 2008, when he was working as a full-time Navy reservist, according to the Pentagon. He was discharged from the Navy in January 2011 after a series of run-ins with his military superiors and police. 
 
 In September 2012, a Hewlett-Packard subcontractor called The Experts hired Alexis and said it confirmed his security clearance with the Defense Department. Thomas Hoshko, the company’s chief executive, said he confirmed the status again in late June of this year, when Alexis returned to work for the firm after a brief hiatus. 
 
 A background check done by a private contractor at the time turned up only a minor traffic violation, according to Hoshko. “It came back clean,” he said. 
 
 Alexis worked as a subcontractor helping to update and replace computers for Navy and Marine Corps installations. Since July, the 34-year-old had worked at six different naval locations, including facilities in Arlington, Va., Cherry Point, N.C., and Stafford, Va. He worked at the Navy Yard for several days before the shooting. 
 
 It is unclear why the Defense Department approved Alexis’s security clearance after his 2004 arrest in Seattle for shooting out the tires of a car. Thomas Richards, a spokesman for the Office of Personnel Management, said the office conducted only one security review of Alexis, in 2007, and that it turned up his 2004 arrest in Seattle. 
 
 He maintained his clearance despite more recent brushes with the law and a pattern of misconduct that preceded his discharge from the Navy. Alexis was arrested on charges of disorderly conduct in DeKalb County, Ga., in 2008, and after he fired a shot into his apartment ceiling in Texas in 2010. 
 
 A Defense Department official said that lower-level clearances such as the one granted to Alexis are typically good for 10 years. Former military employees who become private-sector contractors can also maintain their clearance during that time. 
 
 The official said a person can keep a clearance “in the absence of unadjudicated derogatory information.” 
 
 The agency did not conduct a new background check either last year, when Alexis was first hired as a military contractor, or this summer, when Alexis was seeking a second stint with the contracting firm, people familiar with his hiring said. Instead, the company hired an approved background screening firm that confirmed with the Defense Department that Alexis’s security clearance remained valid. 
 
 A secret-level clearance requires far less-intensive digging than one for top-secret clearance, and involves only a check of the FBI database, military records and data from law enforcement agencies where an applicant has lived, worked or attended school during the past five years. It does not require interviews with family members, co-workers or employers. 
 
 Hoshko told The Washington Post that he would not have hired Alexis if he had known about his arrests. 
 
 “Anything that suggests criminal problems or mental-health issues, that would be a flag,” he said. “We would not have hired him.” 
 
 No one in the company was made aware of the past incidents, he said. “If there’s not full disclosure on this, how do they expect us to make good decisions about who to trust and hire?” 
 
 Hoshko said his company and other contracting firms rely on the military to approve the security clearances of their employees, and he fears that budget crunches have led to faster and less thorough checks. His company hired a private firm — in September 2012, when Alexis first came to The Experts, and in June 2013, when he returned for another stint — to conduct a criminal background check of Alexis. As part of the company’s standard procedure for hiring new employees and rehiring old ones, the company also verified with the Defense Department both times that Alexis’s security clearance remained in force and conducted new drug tests. 
 
 Congressional leaders on Tuesday called for investigations and hearings into how the military screens contractors for classified work and entry to its bases. Sen. Kelly Ayotte (R-N.H.) asked the Senate Homeland Security and Governmental Affairs Committee to hold a hearing into contractor hiring practices at military installations, while Sen. Claire McCaskill (D-Mo.) wrote to Navy Secretary Ray Mabus seeking answers about oversight of contractor access and flaws in security clearances. 
 
 A report released Tuesday by the Defense Department’s inspector general also found serious deficiencies in a Navy screening program for people who didn’t have standard credentials. The program does not apply to contractors such as Alexis, but congressional staffers say it indicates another serious deficiency in the screening system. 
 
 Auditors found 52 convicted felons who received routine, 
 
 unescorted access to naval facilities through the program, known as the Navy Commercial Access Control System. The inspector general said the program, developed in 2010 to check the credentials of occasional contractors, created “a false sense of security” and should be abandoned immediately. 
 
 In one example, the report said an individual was given unescorted access to a base in 2011 for more than three months before it was discovered he had been convicted years earlier of “indecent liberties with a child,” a felony. Several other felonies also weren’t caught in the screening, including convictions for assault, theft and “throwing a missile at an occupied vehicle.” 
 
 Hoshko said he was disturbed to learn from The Post and other news outlets about police reports alleging that Alexis shot out a construction worker’s tires in Seattle in 2004 and fired a bullet into the ceiling of his Fort Worth apartment in 2010. 
 
 “If I can find this out just by doing a Google search, that is sad,” Hoshko said. “Anything that suggests criminal problems or mental-health issues, that would be a flag. We would not have hired him.” 
 
 Sen. Jon Tester (D-Mont.) received staff briefings on the case Tuesday and has authored legislation that would provide more funding to ferret out screening flaws. 
 
 “Corners are obviously being cut,” Tester said. “We had Snowden earlier this year and now the Navy Yard tragedy. We have to fix this.” 
 
 Sen. Thomas R. Carper (D-Del.) chairman of the Homeland Security and Governmental Affairs Committee, said he plans to investigate “a number of things” in the coming weeks — especially how Alexis could have been employed by a federal contractor despite his arrest records and treatment for mental illness. 
 
 “What is the responsibility of our government and contractors to vet employees and from time to time reinvestigate those employees, if concerns arise about someone?” Carper asked. “What kind of clearance or clearances did this suspect possess? What kind of background check did he undergo in order to get his clearance? Were his clearances up to date? Is there some quality problem with the quality process of granting those clearances? And maybe a third one is what can we learn from this incident to help make this installation and other military installations and federal buildings safer, so that some good could come out of something that was awful.” 
 
 Hoshko, whose company is based in Fort Lauderdale, Fla., said he applauds Congress’s revived interest in the rigor of security clearances, the vast majority of which are handled by private firms. 
 
 “You have to more seriously look at the people’s backgrounds,” Hosh­ko said. “If he had a mental background, we would have wanted to know it. . . . The whole [security clearance process] needs to be reviewed top to bottom.” 
 
 Alexis began working for The Experts as an hourly computer technician in September 2012 at a U.S. military base in Japan and finished his work in Japan in January 2013. 
 
 “There were no incidents,” Hosh­ko said. “The guys liked him.” 
 
 He took a break, according to co-workers, because he wanted to go back to school. 
 
 He returned to work on The Experts’ subcontract in July. Alexis told one of his colleagues that he was returning to the contracting world “because school didn’t pay,” Hoshko said. 
 
 Marjorie Censer, Alice Crites, Ed O’Keefe and Craig Whitlock contributed to this report. ||||| WASHINGTON—The U.S.Navy failed to follow up on a police report last month that military contractor Aaron Alexis was hearing voices, Pentagon officials said Wednesday, missing what could have been a crucial opportunity to intervene and prevent Monday's shooting spree at the Washington Navy Yard. 
 
 Six weeks before 12 people were killed and eight more injured at the Navy facility in Washington, police in Newport, R.I., called the local Navy base to report an unusual incident with the suspected shooter, who was working on the base at the time. Mr. Alexis had called the Newport police from his hotel room there on Aug. 7, identified himself as a Navy contractor, and told officers he was hearing voices and being followed by people using a microwave machine to disrupt his sleep. 
 
 Enlarge Image Close Getty Images Secretary of Defense Chuck Hagel, left, and Chairman of the Joint Chiefs of Staff Gen. Martin E. Dempsey brief the press at the Pentagon on Wednesday. 
 
 Enlarge Image Close Getty Images A police officer checks a driver's ID at the entrance to the Washington Navy Yard on Tuesday, a day after contractor Aaron Alexis allegedly killed 12 people. 
 
 Enlarge Image Close Associated Press Bishop Gerald Seabrooks, shown in Brooklyn on Wednesday, read a statement by Cathleen Alexis, mother of the suspect. 
 
 The Navy security official who took the call from local police never passed it along for further investigation, officials said, missing a potential warning sign. "There is no indication that the information went beyond the Naval security force" in Rhode Island, one Navy official said. 
 
 A second Pentagon official defended the Navy security officer's decision not to alert other people at the base, even though Mr. Alexis was working there at the time. The fact that Newport police didn't view Mr. Alexis as a danger probably had an impact on the security officer's view of the risks the contractor posed to the base, he said. 
 
 "The base security personnel did not deem the report to represent a physical threat to the installation," the official said. 
 
 Related Video President Obama has ordered a review of security in Federal buildings, including embassies, following the mass shooting in Washington's Navy Yard Monday. WSJ's Jared Favole explains what the review will mean for safety for federal employees and contractors. 
 
 Mr. Alexis, a former Navy reservist, also visited Veterans Affairs hospital emergency rooms twice in late August complaining of insomnia, and he received medication. During both visits—in Providence, R.I., on Aug. 23 and in Washington, D.C., on Aug. 28—he said, when asked, that he didn't have anxiety, depression or thoughts of hurting himself or others. That would have required doctors to alert authorities of potential danger. 
 
 The VA said Mr. Alexis enrolled in VA health care in February 2011 and had never sought an appointment with a mental-health specialist. The VA also said that Mr. Alexis received a $395 monthly disability benefit for orthopedic issues and tinnitus, which is the perception of sound when no external sound is present. 
 
 The August police incident is one of several red flags the military is investigating to figure out how Mr. Alexis was able to have "secret" security clearance, get a job at the Navy Yard and bring a weapon onto the secure military facility, where authorities say he launched a shooting spree before being shot dead by police. 
 
 Speaking publicly for the first time since the Monday morning shooting, Defense Secretary Chuck Hagel said Wednesday that the military missed several warning signs about Mr. Alexis, who had a yearslong history of mental-health problems and a series of run-ins with the law. "Obviously, when you go back in hindsight and look at this, there were some red flags," Mr. Hagel told reporters at the Pentagon. "Should we have picked them up? Why didn't we? How could we have? All those questions need to be answered." 
 
 Mr. Hagel has ordered a broad review of security and background procedures to figure out what shortfalls exist in the process. "Where there are gaps, we will close them," he said. "Where there are inadequacies, we will address them. And where there are failures, we will correct them." 
 
 Lawmakers from both parties are demanding answers and seeking changes to the security-clearance process that has approved secret access to people like Edward Snowden, the former intelligence contractor who has leaked classified documents on the nation's most secretive surveillance programs to the global media. 
 
 As government investigators pieced together Mr. Alexis's life, the reputed shooter's mother apologized for her son's actions. 
 
 "I am so, so very sorry that this has happened. My heart is broken," Cathleen Alexis said in a statement read by a clergyman outside her home in the New York City borough of Brooklyn. She added in the statement: "I don't know why he did what he did, and I'll never be able to ask him why." 
 
 At the time of the shooting, Mr. Alexis was working at the Navy Yard on an Internet project for the Experts, a Florida-based military subcontractor. The company said it hired a background-check firm to carry out two examinations of Mr. Alexis that turned up nothing more serious than a traffic violation. 
 
 On Wednesday, military officials said there were few safeguards in the current system that would have raised alarms about Mr. Alexis. 
 
 Mr. Alexis first received "secret" security clearance in 2008 shortly after joining the military as a Navy reservist. He underwent a government background check that unearthed a 2004 arrest for "malicious mischief" in Seattle, where he was questioned after shooting out the tires of a car in what he characterized as an anger-fueled "blackout," according to the Office of Personnel Management, which oversaw the background check. 
 
 Despite a spotty military record, Mr. Alexis was given an honorable discharge, which allowed him to retain his security clearance. 
 
 —Danny Gold in New York contributed to this article. 
 
 Write to Dion Nissenbaum at dion.nissenbaum@wsj.com 
 
 A version of this article appeared September 19, 2013, on page A3 in the U.S. edition of The Wall Street Journal, with the headline: Pentagon Missed Red Flags on Shooter.
– The Los Angeles Times sheds more light on how Navy Yard gunman Aaron Alexis was able to get secret-level security clearance from the Navy, despite the fact that he had been arrested in 2004 for an incident involving a gun. Alexis did not mention the incident on the security questionnaire he filled out three years later, but the Navy's Office of Personnel Management learned about it after doing a fingerprint check. He was asked about it and claimed all he did was deflate a man's tires. In reality, he shot out the man's tires, according to the police report filed in Seattle. Alexis said he did not disclose the incident because the charge was dismissed and his lawyer had told him it would be wiped from his record. Investigators did not interview anyone else about the incident, the Washington Post reports, and Seattle police refused to provide the records related to the incident, according to the personnel office. So the Navy cleared Alexis in March 2008 based on what it knew. (The LAT notes the only red flag was his credit history.) The full picture of the 2004 incident didn't emerge until after the Navy Yard shootings, says a senior Navy official. Now, the secretary of the Navy has recommended to Defense Secretary Chuck Hagel that security reviews in the future include all police reports—even those that did not result in charges, the New York Times reports.