The stunning explosion that leveled a duplex in Arlington, Virginia, in December was intentionally caused by a resident who was found dead inside, investigators found.
James Yoo intentionally caused the explosion caught on video using up to 35 gallons of gasoline that he set ablaze, local and federal officials said at a news conference Friday.
The Dec. 4, 2023, explosion rocked a Northern Virginia neighborhood with a powerful blast and destroyed the home of a family who lived adjacent to Yoo.
Investigators determined that Yoo intentionally triggered the blast in the basement using gasoline in three containers, including one with a capacity of up to 20 gallons. He likely set the gasoline ablaze using a gun, flare gun, matches or a lighter, a U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) official said.
“After a thorough and comprehensive investigation was conducted, our investigators determined the incident was an intentional act by the decedent,” said Ioannis Douroupis, resident agent in charge of ATF's Washington Field Office.
“The decedent applied gasoline in the basement of the residence and ignited the vapors,” he continued.
Yoo had previously been presumed dead. In the update Friday, officials confirmed that human remains found in the wreckage of the duplex were Yoo’s. He died of blunt force trauma and burns, officials said.
For the first time, police released officer body camera and dash cam video footage. It shows new perspectives on the tragedy.
A duplex destroyed on video
Yoo fired flares from an upstairs window of his home in the 800 block of N. Burlington Street, near the Ballston area, at least 40 times the afternoon and evening of Dec. 4, police said.
"Arlington County police! Stop shooting the flares!" an officer can be heard shouting on video.
A man's hand can be seen firing the flare gun out the window.
Over the course of hours, police repeatedly warned him to stop and then warned that they would enter his home. He began shooting gunfire from the house. During the standoff, natural gas to the duplex was turned off.
Police used an armored vehicle to breach the front door, and more gunshots could be heard from inside the house.
Video shows the brick duplex in the moments before the blast. Just weeks before Christmas, an inflatable snowman is set up in front of Yoo’s next-door neighbors’ home.
Then at 8:24 p.m., orange flames shoot into the air. In an instant, the roof collapses, the walls bulge out, and bricks and glass fly in every direction.
On police body camera footage, officers can be heard swearing and yelling in disbelief. They ran to neighbors’ homes to pound on their doors and tell them they needed to evacuate.
Neighbors described strange behavior
Items found in Yoo’s home after the explosion included at least three guns, two flare guns, ammunition and flares.
There is no nexus to terrorism or any continuing threat, the FBI found.
Arlington police had no documented prior incidents with Yoo, other than two “noise-type complaints,” Chief of Police Andy Penn said.
Yoo had repeatedly contacted the FBI about fraud he believed had been perpetrated against him. Those tips did not result in any investigations, an official said.
Yoo publicly aired grievances against multiple people in his life. On LinkedIn, he posted paranoid rants about his neighbors and a former coworker. He also filed multiple federal lawsuits that were dismissed as frivolous against his ex-wife, younger sister, a moving company and the New York Supreme Court.
Neighbors reported strange behavior, including Yoo having large quantities of lighter fluid, charcoal and bleach delivered to the home, covering the windows with black trash bags and rarely stepping outside.
News4 spoke with residents of the area and some said the new details from investigators bring some closure.
“It’s creepy hearing about stockpiling and things like that, but I’m glad it’s over,” one man said.
The family who lived in the other half of the duplex said via lawyers on Friday that they had no comment.
When asked about Yoo’s possible motive, Arlington’s police chief said some questions may always go unanswered.
“As far as motive, unfortunately, we’re not gonna know,” he said.
Stay with NBC Washington for more details on this developing story.
