TWIN FALLS, Idaho (AP) — The 24-year-old suspect in a fatal weekend shooting at an In-N-Out Burger restaurant in southern Idaho died of a self-inflicted gunshot wound, police said Sunday. Investigators are confident that the gunman, identified as Chad Williams, acted alone during the shooting Saturday in Twin Falls, Police Chief Matthew Hicks said at a news conference. In all, three people died and seven others were injured at the recently opened restaurant in the southern Idaho city of about 56,000 people. Authorities said Sunday that two of the injured were treated at a hospital and released, three were listed as stable, and two were in critical condition.Hicks said an off-duty state trooper and an armed citizen both fired back and diverted the gunman.“We believe their actions helped drive the suspect away from the scene, preventing further casualties,” the chief said. “We want to take a moment and commend the actions of the off-duty officer and the citizen, and their heroic action to stop this incident.”Hicks said detectives are working to determine Williams’ motivations, and said the suspect’s family was cooperating fully with law enforcement.He also warned of misinformation spreading online identifying a different man as the shooter, saying the man had “no involvement in this incident whatsoever.”