Aaron Alexis was born on May 9, 1979, in Queens, New York City. He grew up in Brooklyn, New York, and later lived in Fort Worth, Texas. After completing high school, Alexis joined the Navy in May 2007. He served as an aviation electrician's mate in Fleet Logistics Support Squadron 46 at Naval Air Station Joint Reserve Base Fort Worth. He reached the rank of petty officer third class during his service. Alexis was honorably discharged from the Navy on January 31, 2011.

During his time in the Navy, Alexis faced a number of issues. He was cited for misconduct at least eight times. In 2010, he was arrested in Fort Worth for discharging a weapon within the city limits. Earlier, in 2004, he had been arrested in Seattle for malicious mischief, where he shot out the tires of another man's vehicle during what he called an anger-fueled blackout. In 2008, he was also arrested in DeKalb County, Georgia, for disorderly conduct. None of these arrests led to prosecutions, which meant he did not receive any formal penalties for his actions.

After leaving the Navy, Alexis worked in various jobs. He held a secret-level security clearance, which he received in March 2008. This clearance allowed him to work with sensitive information for the Navy. He worked on the Navy Marine Corps Intranet network for a subcontractor in Japan from September 2012 to January 2013. After returning from Japan, he expressed frustration about his work situation and reported feeling discriminated against.

In terms of education, Alexis was studying for a bachelor's degree in aeronautics at Embry-Riddle Aeronautical University. He practiced Buddhism and was described by friends as a nice person who enjoyed meditation. However, reports later indicated he had been experiencing significant mental health issues. In August 2013, he filed a police report in Rhode Island, claiming he was hearing voices and felt he was being harassed.

Overall, Aaron Alexis' early life involved a mix of personal struggles, military service, and professional ups and downs. His experiences shaped his life leading up to his later actions.

On September 16, 2013, Aaron Alexis left a hotel and drove to the Washington Navy Yard, arriving around 7:53 a.m. He entered the Navy Yard using a valid pass and went to Building 197. At approximately 8:08 a.m., he was seen on surveillance footage entering the building carrying a disassembled shotgun in a bag. He went to the fourth floor, where he had worked previously. There, he assembled the shotgun in a bathroom.

The shooting began at 8:16 a.m. Alexis fired at people in a cubicle area, hitting six individuals. Five of these people died, and one survivor sustained serious injuries. Within a few minutes, he continued shooting, moving to the third floor, where he fatally shot two more people. Over the next few minutes, he walked through the building, shooting and wounding several others.

Police received the first emergency calls at 8:17 a.m. By 8:23 a.m., officers began arriving at the scene. However, confusion about the shooter's location slowed their response. Meanwhile, Alexis was on the first floor and shot Richard Ridgell, a security officer. He took Ridgell's Beretta pistol and continued to fire at others in the building.

At approximately 8:34 a.m., Alexis encountered two men outside the building. After realizing his shotgun was empty, he used the stolen Beretta to shoot one man while the other escaped unharmed. Reports of a second shooter emerged, but authorities later clarified that Alexis acted alone.

As police officers searched the building, Alexis concealed himself in a cubicle area on the third floor. He opened fire on officers when they entered the area, injuring an officer in the leg. A few minutes later, other officers returned fire and shot Alexis in the head. He was declared dead at 11:50 a.m.

In total, 13 people died as a result of the shooting, including Alexis, and eight others were injured. The shooting prompted discussions about security at military facilities and the mental health of the shooter.