Washington Navy Yard shooting

On February 20, 2014, a ceremony was held to honor the over 170 law enforcement officers, including 57 D.C. Metropolitan Police officers, who responded and entered the building to search for the shooter. Specifically, MPD Officers Scott Williams and Dorian DeSantis were given the Medal of Valor, U.S. Park Police Medal of Honor, and the Blue Badge Medal for their roles during the gun battle.

On December 19, 2014, President Obama signed a bill authorizing the establishment of a memorial to the shooting. A remembrance wall was dedicated the following February.

The Washington Navy Yard shooting occurred on September 16, 2013, when 34-year-old Aaron Alexis fatally shot 12 people and injured three others in a mass shooting at the headquarters of the Naval Sea Systems Command (NAVSEA) inside the Washington Navy Yard in southeast Washington, D.C. The attack took place in the Navy Yard's Building 197; it began around 8:16 a.m. EDT and ended when police killed Alexis around 9:25 a.m. It was the second-deadliest mass murder on a U.S. military base, behind the 2009 Fort Hood shooting.

After the Navy Yard shooting, the media speculated that Alexis had appeared to be suffering from mental illness. The media reported that Alexis had filed a police report in Rhode Island on August 2, 2013. He claimed to be the victim of harassment and that he was hearing voices in his head. According to an FBI official after the shooting, Alexis was under the "belief that he was being controlled or influenced by extremely low-frequency electromagnetic waves". A message later obtained by federal authorities from Alexis's personal computing devices said, "Ultra low frequency attack is what I've been subject to for the last 3 months. And to be perfectly honest, that is what has driven me to this."

On August 4, 2013, naval police were called to Alexis's hotel at Naval Station Newport and found that he had "taken apart his bed, believing someone was hiding under it, and observed that Alexis had taped a microphone to the ceiling to record the voices of people that were following him". At the time of the incident, he was working for the contractor at the base.

At the time of the shooting, Alexis had been working for a subcontractor on a Hewlett-Packard Enterprise Services contract supporting a Navy-Marine Corps (NMCI) computer network. Alexis arrived in the Washington, D.C., area on or around August 25, 2013, and stayed at various hotels to escape the voices. At the time of the massacre, he had been staying with five other civilian contractors at the Residence Inn hotel he booked into in southwest Washington, D.C., since September 7.

The Navy Yard reopened and resumed usual operations on September 19, 2013. Building 197 reopened on February 2, 2015. In October 2013, the Navy announced a repair-and-restoration contract for the building; the contract indicated that "the repairs shall be done in a manner that changes the feel, finish, appearance and layout of the space, creating a different sense of place and mitigating the psychological and emotional impacts that the facility itself could have on returning occupants". The building, renamed after Joshua Humphreys, reopened in 2015. The renovations, costing approximately $44 million, include a reflection area and new visitors' entrance, new flooring, furnishings, and an updated cafeteria.

On September 25, 2013, Hewlett Packard fired the computer firm The Experts, which employed the shooter, over "its failure to respond appropriately" to the Washington Navy Yard shooter's mental health issues.

On October 31 and December 17, 2013, the Senate's Committee on Homeland Security and Governmental Affairs held hearings examining government clearances, background checks, and physical security for federal facilities in the wake of the shootings.

Alexis worked in Japan from September 2012 to January 2013 on the Navy Marine Corps Intranet network for an HP Enterprise Services sub-contracting company called The Experts. After returning from Japan, he expressed frustration to a former roommate that he had not been paid properly for the work that he performed. Another roommate said that he would frequently complain about being the victim of discrimination. In July 2013, he resumed working for The Experts in the United States.

According to a Navy official, Alexis was cited on at least eight occasions for misconduct. In 2010, he was arrested in Fort Worth for discharging a weapon within city limits. He was also arrested in 2004 in Seattle, Washington, for malicious mischief after shooting out the tires of another man's vehicle in what he described as an anger-fueled "blackout", and for disorderly conduct in 2008 in DeKalb County, Georgia. None of his arrests led to prosecution, so there was no penalty for his actions.

Alexis received a secret-level security clearance in March 2008 that was valid for ten years. Following the Navy Yard shooting, it was found that the federal personnel report, which led to the clearance's approval, did not mention that his 2004 arrest had involved a firearm. Alexis said on his clearance application that he had never been charged with a felony and that he had not been arrested in the last seven years; the personnel report said that he had given these answers because the 2004 charge had been dismissed. This security clearance investigation was conducted by USIS, the same contractor that had vetted Edward Snowden. The Department of Justice has filed fraud charges against USIS in a whistleblower case filed as United States of America ex rel. Blake Percival vs USIS.

Alexis was born May 9, 1979, in the New York City borough of Queens. He grew up in Brooklyn and was a resident of Fort Worth, Texas. He joined the Navy in May 2007 and served in Fleet Logistics Support Squadron 46 at Naval Air Station Joint Reserve Base Fort Worth. His rating was aviation electrician's mate, and he had attained the rank of petty officer third class when he was honorably discharged from the Navy on January 31, 2011, although the Navy originally intended for him to receive a general discharge.