The Washington massacre gunman used a valid security pass to get inside the navy complex where he killed 12 people but the motive for the shootings was still a mystery, investigators said.
The lone gunman, who was eventually shot dead by police was 34-year-old Aaron Alexis, a defence contract employee and former navy reservist.
He was described as a Buddhist who had also had a violent temper, complained about the navy and being a victim of discrimination, and had several run-ins with the law, including two shootings.
The shootings in the Washington Navy Yard reignited the debate over gun control in the United States.
US president Barack Obama lamented “yet another mass shooting” and promised to make sure “whoever carried out this cowardly act is held responsible.” He has been powerless to get gun control legislation passed by Congress. Monday’s onslaught at a single building at the highly secure Navy Yard unfolded about 8.20am in the heart of the US capital.
Alexis carried three weapons: an AR-15 assault rifle, a shotgun, and a handgun that he took from a police officer at the scene.
The AR-15 is the same type used in last year’s mass shooting at a Newtown, Connecticut, school that killed 20 pupil and six staff.
The weapon was also used in the shooting at a Colorado cinema that killed 12 and wounded 70. For much of the day, authorities said they were looking for a possible second attacker who may have been disguised in an olive-drab military-style uniform.
But later they said they were convinced the shooting was the work of a lone gunman, and the lockdown around the area was eased. “We do now feel comfortable that we have the single and sole person responsible for the loss of life inside the base today,” Washington police chief Cathy Lanier said.
The FBI took charge of the investigation. The dead ranged in age from 46 to 73. Some were civilian employees and contractors, rather than active-duty military personnel.
Alexis was an employee with The Experts, a company that was a defence department subcontractor on a Navy-Marine Corps computer project and had access to the Navy Yard as a defence contractor using a valid pass.
Alexis, who was born in New York but whose last known address was in Forth Worth, Texas, served as a navy reservist from 2007 to 2011 when he was discharged following a “pattern of misconduct,” a US department of defense official was quoted as saying in multiple news reports.
He worked as an aviation electrician attached to a support squadron based in Forth Worth, Texas where he worked on C-40 plans, the military version of the Boeing 737 used as a cargo plane.
More recently, he had been working as a military contractor through the HP subcontacting firm. The suspect was identified using fingerprints and a legally valid identification badge that allowed him to enter the Washington naval facility. There were no metal detectors at the entrance to the facility. The accused man also had previous run-ins with law enforcement officials.
Police arrested Alexis in Seattle in 2004 for shooting the tyres of another man’s vehicle in what he told detectives was an anger-fuelled “blackout,” according to the police report. He was arrested again on September 5th 2010, in Fort Worth, on suspicion of discharging a weapon. He escaped prosecution arguing that the gun had discharged accidentally as he was cleaning the firearm.
Witnesses described how he opened fire from a fourth-floor vantage point, aiming down on people on the main floor, which includes a glass-walled cafeteria.
In the confusion, police said initially they were searching for two accomplices who may have taken part in the attack — one carrying a handgun and wearing a tan Navy-style uniform and a beret, the other armed with a long gun and wearing an olive-green uniform.
But as the day wore on, they dropped one person and then the other as suspects. As tensions eased, Navy Yard employees were gradually released from the complex, and children were let out of their locked-down schools.
Washington Navy Yard, the oldest naval facility in the country, is home to the largest of five US naval command centres, which buys and maintains ships and submarines and their combat systems.
About 3,000 staff worked at the main naval headquarters facility, known as Building 197 where the shootings occurred. The naval centre is located about three miles south-east of the White House and just over a mile south of the US Capitol along the Anacostia River near the baseball stadium of the Washington Nationals.
Yesterday’s mass shooting was the deadliest at a US military installation since a US army major killed 13 people and injured 28 at a Fort Hood, Texas in November 2009.
