The suspect in a fatal shooting at a fast-food restaurant in Twin Falls, Idaho, died from a self-inflicted gunshot wound, police announced Sunday. Investigators believe the 24-year-old gunman, identified as Chad Williams, acted alone in the incident that left three people dead and seven others injured.

Police Chief Matthew Hicks stated at a news conference that an off-duty state trooper and an armed citizen, whose identities have not been released, fired shots that diverted Williams away from the restaurant, potentially preventing further casualties. Hicks commended their actions as heroic.

Authorities are still working to determine Williams' motivations, and his family is cooperating with the investigation. Police also addressed misinformation circulating online, warning the public about false identifications of the shooter.

One of the deceased was an employee of the In-N-Out Burger restaurant, the company's owner, Lynsi Snyder, confirmed in a statement. The FBI has asked the public to submit any images or videos related to the shooting. The In-N-Out had recently opened on July 24, marking the California-based chain's expansion into Idaho.

Witnesses described a chaotic scene. One witness, Lane Koehn, reported seeing a person with a rifle emerge from the drive-thru, followed by a man with a pistol who began firing at the shooter. Koehn also saw an In-N-Out employee drag a wounded coworker to safety in the parking lot.

Another witness, Haley Dodaro, was in the drive-thru line when she saw people running from the restaurant and was told by a traffic director that there was a shooter. Nayeli Rodriguez was inside with her daughters when shots were heard from the kitchen. An employee alerted customers to the shooting and told them to get down. Rodriguez and her daughters were among the last to exit the building, with the help of other individuals.

Twin Falls, located in southern Idaho, has a population of approximately 56,000. At the time of the report, two of the seven injured individuals had been released from the hospital, three were listed in stable condition, and two were in critical condition. The FBI is encouraging the public to submit any relevant media to aid the investigation.