Man Arrested After Molotov Cocktail Thrown at Sam Altman's SF Home

A bottle stuffed with a flaming rag was hurled at the metal gate of Sam Altman's Russian Hill home at 3:40 a.m. Friday, triggering an arson investigation that ended with a 20-year-old man in handcuffs outside OpenAI's Mission Bay headquarters less than two hours later.

Daniel Alejandro Moreno-Gama was booked into San Francisco County Jail Friday afternoon on suspicion of attempted murder, arson, and possession or manufacture of an incendiary device. Security guards stationed at 855 Chestnut St. extinguished the fire at the exterior gate before SFPD officers arrived at 4:12 a.m. The entire sequence was captured on surveillance cameras outside the home. No injuries were reported.

After fleeing on foot, Moreno-Gama crossed the city to OpenAI's headquarters at 1455 Third St. in Mission Bay. At approximately 5:07 a.m., officers responded to reports of an unknown man threatening to burn the building down. Responding officers recognized him from the earlier surveillance footage and detained him on the spot. Police dispatcher audio captured someone reporting: "Someone threw a Molotov cocktail slash sticky bomb at the gate of Sam Altman, CEO of OpenAI's residence."

OpenAI spokesperson Jamie Radice confirmed both incidents: "Early this morning, someone threw a Molotov cocktail at Sam Altman's home and also made threats at our San Francisco headquarters. Thankfully, no one was hurt. We deeply appreciate how quickly SFPD responded and the support from the city in helping keep our employees safe. The individual is in custody, and we're assisting law enforcement with their investigation."

Altman, who purchased the 5,400-square-foot Chestnut Street property in January 2025 through an affiliate managed by his cousin Jennifer Serralta, responded via a personal blog post Friday afternoon. He shared a photo of his husband and their son. "Normally we try to be pretty private, but in this case I am sharing a photo in the hopes that it might dissuade the next person from throwing a Molotov cocktail at our house, no matter what they think about me," he wrote, adding a call for broader de-escalation: "we should de-escalate the rhetoric and tactics and try to have fewer explosions in fewer homes, figuratively and literally."

The FBI confirmed it was aware of the incident and coordinating with SFPD. The San Francisco District Attorney's Office indicated it could be next week before a decision is made on whether the case proceeds locally or in federal court. SFPD's Special Investigations and Arson units are leading the investigation; no motive had been publicly disclosed as of Friday. OpenAI told employees Friday there was no immediate threat to staff but that increased police and security presence would be stationed at the Mission Bay campus.

Friday's attack is the most serious in a pattern of escalating threats against OpenAI. In November 2025, a 27-year-old anti-AI activist named Sam Kirchner prompted the lockdown of OpenAI's San Francisco offices after threatening to murder people at the company; an SFPD bulletin at the time noted callers told police Kirchner had expressed a desire to acquire high-powered weapons to carry out those threats.

Altman's Chestnut Street property is the centerpiece of a substantial real estate footprint in the neighborhood. He also owns the adjoining lots at 952 and 954 Lombard St., and in March 2020 paid $27 million for 950 Lombard St., at the time the most expensive residential listing in San Francisco. Formal charges and a first court appearance for Moreno-Gama are expected in the coming days as investigators work to establish a motive and determine whether he acted alone.