On April 17, 2025, a mass shooting occurred on the campus of Florida State University (FSU) in Tallahassee, Florida, United States. Two university employees were killed and six others wounded in an attack lasting approximately three minutes near and inside the Student Union building, just before noon. The two people killed were Robert Morales, 57, the campus dining director, and Tiru Chabba, 45, a regional vice president at Aramark Collegiate Hospitality. Phoenix Ikner, a 20-year-old FSU student, was shot in the jaw by campus police and taken into custody. A Glock 21 handgun belonging to his stepmother, a Leon County Sheriff's deputy, was used in the attack; a shotgun also found at the scene had not been fired.

Ikner, born Christian Gunnar Eriksen, was a dual American-Norwegian citizen who had experienced a turbulent childhood marked by a bitter parental custody dispute that included an international abduction by his biological mother. He later espoused white supremacist and far-right views and was removed from a political group at Tallahassee State College. Court documents later revealed that Ikner had used ChatGPT extensively in the hours before the attack, asking the chatbot questions about likely media coverage of a mass shooting and about the busiest times at the Student Union.

After spending a month hospitalized, Ikner was charged with two counts of first-degree murder and seven counts of attempted first-degree murder. He was indicted by a grand jury on May 14, 2025, and denied bond. Florida prosecutors announced in June 2025 that they would seek the death penalty. The trial, initially scheduled for early 2026, was later postponed to October 19, 2026.

The shooting prompted an outpouring of reaction from politicians, activists, and survivors of previous mass shootings, including the Parkland shooting. Civil lawsuits followed on behalf of the victims' families, including a planned suit against OpenAI over ChatGPT's alleged role in facilitating the attack. The Florida Attorney General launched a separate criminal investigation into OpenAI's potential liability.

Florida State University is a public research university in Tallahassee, Florida. It maintains 17 colleges as well as 58 centers, facilities, labs, institutes, and professional training programs. In 2023, the university enrolled 43,701 students from all 50 states and 135 countries.

Two acts of mass violence targeting the university or its students had occurred before the 2025 shooting. On January 15, 1978, serial killer Ted Bundy murdered two women at the school's Chi Omega sorority house and injured two others, before attacking another FSU student at a house eight blocks away. A previous shooting occurred in November 2014, when a gunman opened fire in the university's library around midnight, wounding three people before being killed by responding law enforcement.

The suspect arrived at a Florida State University parking garage at approximately 11:00 a.m. and remained there until 11:51 a.m., spending most of that time in his car and occasionally stepping outside. After leaving the parking garage, he drove to a service road beside the Student Union and parked at 11:57 a.m. He got out, aimed a shotgun at a student, but the weapon failed to fire. He returned the shotgun to his vehicle, retrieved his stepmother's Glock handgun, and at 11:57:22 a.m. was captured on CCTV running toward the union with the handgun concealed in his right pocket.

At 11:57:24 a.m., the suspect aimed his handgun and fired the first shots outside the Student Union, wounding two students on the lawn while firing at several others. Video shows him in shorts and a T-shirt walking and firing across the lawn. He then ran to the Student Union and entered the building at 11:58:22 a.m., chasing people through the corridors. At 11:58:36 a.m., he chased campus vendor Tiru Chabba outside the building and shot him, then ran west. At 11:58:51 a.m., he returned and shot Chabba again. At 11:58:54 a.m., he ran toward the union's bookstore, firing at a group of students outside and hitting three of them non-fatally. He then returned to the bookstore entrance and fired at another student, missing.