Man Convicted of Arson in SF Transbay Terminal

San Francisco prosecutors said a jury convicted Viengphet Sasone on May 21 after concluding he possessed an incendiary device in connection with a fire inside the Transbay Terminal late last year. The conviction followed a trial over a blaze that authorities said began before dawn on Dec. 13, 2025, in the Muni plaza under an escalator. District Attorney Brooke Jenkins said the case turned on evidence that Sasone set bedding on fire atop a garbage can and was still near the scene when security staff intervened. The fire was extinguished before it spread, and police arrested Sasone at the terminal, according to the district attorney’s office. ### Who was convicted, and of what charge? Viengphet Sasone, 48, was convicted of possession of an incendiary device under California Penal Code 453(a), according to a May 21 statement from the San Francisco District Attorney’s Office. Prosecutors said the verdict came after a jury trial tied to the Transbay Terminal fire. Brooke Jenkins said her office secured the conviction after presenting testimony and evidence about the fire and the response by terminal staff and police. The district attorney’s office identified the case as San Francisco Superior Court number 25027264. ### What do prosecutors say happened inside the terminal? December 13, 2025, at about 4:30 a.m. is when prosecutors said the fire began in the Muni plaza of the Transbay Terminal in San Francisco. According to the district attorney’s office, Sasone set bedding on fire on top of a garbage can under an escalator. The Transbay Terminal security response became a central fact in the case. Prosecutors said one security guard saw Sasone by the fire and alerted a colleague, who used a fire extinguisher to put the blaze out before it grew. ### Why did prosecutors describe the fire as especially dangerous? Brooke Jenkins said Sasone’s conduct was “incredibly dangerous” and said the quick response by Transbay security staff prevented what could have been significant damage to the terminal. Jenkins also said the fire could have disrupted passengers who rely on the facility to travel to and from downtown. Assistant District Attorney Kirk Earl said the blaze was still small when it was extinguished, but added that any fire in public has the potential to cause serious harm. Earl said the verdict showed that “dangerous behavior like this will not be tolerated in San Francisco.” ### What evidence tied Sasone to the fire? San Francisco police officers arrested Sasone at the scene after arriving at the terminal, according to the district attorney’s office. Prosecutors said he was in possession of an orange lighter when officers took him into custody. The district attorney’s office said the prosecution relied on testimony, physical evidence and the police investigation. Jenkins credited the San Francisco Police Department and Transbay staff for what she described as thorough work and coordination with law enforcement. ### Who handled the case for the city? Assistant District Attorney Kirk Earl prosecuted the case, the district attorney’s office said. The office also named paralegal Raquel Paz Aleman and IT support staff Ada Yu and Leland Chan as part of the trial team. San Francisco prosecutors publicly thanked the jury after the verdict. Earl said jurors had carefully considered the evidence presented during trial. ### What happens next in the case? May 21 is the date prosecutors announced the conviction, but the district attorney’s statement did not include a sentencing date for Sasone. The next procedural update is likely to appear in San Francisco Superior Court under case number 25027264 or in a later statement from the district attorney’s office.