The man accused of throwing a Molotov cocktail at OpenAI CEO Sam Altman’s home in San Francisco was opposed to artificial intelligence, writing about AI’s purported risk to humanity and “our impending extinction,” according to court documents.

Authorities allege 20-year-old Daniel Moreno-Gama threw the incendiary device about 4 a.m. Friday, setting an exterior gate at Altman’s home alight before fleeing on foot, police said. Less than an hour later, Moreno-Gama allegedly went to OpenAI’s headquarters and reportedly threatened to burn down the building.

On Monday morning, FBI agents went to Moreno-Gama’s home in Spring, Texas, a suburb of Houston, where they spent several hours before leaving. He has been charged by federal prosecutors with possession of an unregistered firearm and damage and destruction of property by means of explosives.

The FBI’s office in Houston confirmed agents were at the scene but declined further comment. Neighbors described the homeowners as “very nice people” who were involved with their church.

The criminal complaint does not name Altman or OpenAI but both have confirmed they were the targets of the attack. No injuries were reported.

When Moreno-Gama was arrested Friday, officials found a document on him in which he “identified views opposed to Artificial Intelligence (AI) and the executives of various AI companies,” court documents say. The document discussed AI’s purported risk to humanity and “our impending extinction,” according to the criminal complaint.

Authorities allege Moreno-Gama traveled from his home in Texas to San Francisco and visited Altman’s home early Friday morning.

Surveillance video images included in the criminal complaint show a person dressed in a dark hoodie and pants that the FBI alleges is Moreno-Gama approaching the driveway of Altman’s home. In various images, the person can be seen tossing the Molotov cocktail, which landed at the top of a metal gate and started a small fire.

Surveillance video images from outside OpenAI’s headquarters allegedly show Moreno-Gama grabbing a chair and using it to hit a set of glass doors. Authorities said Moreno-Gama was approached by the building’s security personnel, who told investigators he “stated in sum and substance” that he came to the headquarters “to burn it down and kill anyone inside,” according to the complaint.

San Francisco police arrested Moreno-Gama and recovered “incendiary devices, a jug of kerosene, a blue lighter, and a document.” Moreno-Gama was being held Monday in the San Francisco County Jail on various state charges, including possession or manufacture of combustible material or an incendiary device and arson.

The document in which Moreno-Gama discussed his opposition to AI also made threats against Altman, officials said.

“Also if I am going to advocate for others to kill and commit crimes, then I must lead by example and show that I am fully sincere in my message,” Moreno-Gama is alleged by authorities to have written in the document.

Advocacy groups that have issued grave warnings about AI’s risks to society condemned the violence.

Anthony Aguirre, president and CEO of the Future of Life Institute, said in a written statement Friday that “violence and intimidation of any kind have no place in the conversation about the future of AI.”

Another group, PauseAI, said in a statement that the suspect had no role in the group but joined its forum on the social media platform Discord about two years ago and posted about 34 messages there, none containing explicit calls to violence but one that was flagged as “ambiguous.”

Discord said Monday that it has banned Moreno-Gama for “off-platform behavior.”

Hours after the attack on his house, Altman posted a photo of his husband and their toddler in a blog post addressing the threats against him.

“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,” Altman wrote.

He added that “fear and anxiety about AI is justified” but it was important to “de-escalate the rhetoric and tactics and try to have fewer explosions in fewer homes, figuratively and literally.”

Altman has become a preeminent voice in Silicon Valley on the promise and potential dangers of artificial intelligence. The attack comes days after The New Yorker published an in-depth investigation that touched on concerns some people have about him and the company.

Lozano reported from Houston. Associated Press journalist Matt O’Brien contributed to this story from Providence, Rhode Island.