The family of one of the victims of a mass shooting at Florida State University is filing a federal lawsuit against OpenAI claiming its artificial intelligence program ChatGPT contributed to the killing.

Tirus Chabba was one of two people shot to death at FSU during the mass shooting April 17, 2025. His widow, Vandana Joshi, filed the lawsuit with the U.S. District Court for the Northern District of Florida Tallahassee. The suit was also filed on behalf of the couple’s son and daughter.

The 76-page legal filing alleges Phoenix Ikner, who is accused of shooting the victims, planned the shooting with detailed directions provided by ChatGPT. The lawsuit says Ikner was engaged with ChatGPT up to the point he arrived on the FSU campus with a Glock handgun and a Remington shotgun.

According to the lawsuit, while the shotgun initially wouldn’t fire, Ikner got his handgun and proceeded to shoot a total of eight people, six were injured.

“ChatGPT inflamed and encouraged Ikner’s delusions; endorsed his view that he was a sane and rational individual; helped convince him that violent acts can be required to bring about change; assisted him by providing information that he used to plan specifics like what weapons to use and how to use them,” the lawsuit says.

OpenAI officials deny responsibility for the shooting.

“Last year’s mass shooting at Florida State University was a tragedy, but ChatGPT is not responsible for this terrible crime,” OpenAI spokesperson Drew Pusateri told NBC News in an email, adding that OpenAI did everything possible to assist law enforcement.

“In this case, ChatGPT provided factual responses to questions with information that could be found broadly across public sources on the internet, and it did not encourage or promote illegal or harmful activity.”

The lawsuit comes on the heels of a criminal investigation launched by Attorney General James Uthmeier into OpenAI last month. Uthmeier linked his probe to the FSU shootings.

“If it was a person on the other end of that stream, we would be charging them with murder,” Uthmeier said.

Uthmeier expanded that criminal probe in late April to include questions over what role ChatGPT played in the killings of two students at the University of South Florida.