An Off-Duty Officer and an Armed Customer Fired Back at the In-N-Out Gunman. Police Say That Ended It.

A gunman opened fire inside an In-N-Out Burger in Twin Falls, Idaho, shortly before 2:30 p.m. Saturday, killing three people and wounding seven before dying of a self-inflicted gunshot wound. Police have identified the shooter as 24-year-old Chad Williams and say they are confident he acted alone.

Twin Falls Police Chief Matthew Hicks said an off-duty police officer and a civilian who was carrying a handgun both fired at the gunman during the attack. "We believe their actions drove the suspect from the scene, preventing further casualties," Hicks said. Investigators determined that the wound that killed Williams was self-inflicted rather than fired by either of the two people who engaged him.

One of the three people killed was an In-N-Out employee, a woman working her shift when the shooting began. Authorities have not released the names of the dead. Of the seven wounded, Hicks said two were treated and released, three were in stable condition and two were in critical condition, and he cautioned that those figures were preliminary and could change as hospitals updated the department.

The restaurant sits in Twin Falls, a city of roughly 55,000 people about 120 miles southeast of Boise, in the kind of setting that makes an attack of this scale unusual for the state. FBI agents joined local investigators at the scene. A motive has not been established, and Hicks said detectives were still working to determine what drove Williams to the restaurant.

The lunch-hour timing put the restaurant near capacity when the shooting started, which accounts for the ratio of wounded to killed. Ten people were struck in a dining room and parking area that had no cover to speak of, and the response depended on who happened to be standing there. Neither of the two people who fired back was on duty in any official capacity at the moment the shooting began; one carried a badge, the other carried a permit. Investigators will reconstruct the sequence from surveillance video, shell casing positions and the accounts of survivors, a process that in comparable cases has taken weeks to produce a reliable minute-by-minute account.

Hicks also acknowledged the shooter's family in his remarks, saying, "Their hearts are also broken" — an unusually direct nod from a police chief in the first 24 hours of a mass shooting investigation, and one that drew attention in a case where the suspect was a local man rather than someone who traveled to the site.

The details that will drive the political argument were established almost immediately: an armed bystander and an off-duty officer intervened, and police credited that intervention with limiting the toll. Whether the shooter was already committed to ending the attack himself when he was fired upon is one of the questions detectives will try to answer from surveillance footage and the physical evidence inside the restaurant. What is not in dispute is the count: three dead, seven wounded, one suspect dead, on a Saturday afternoon at a fast-food counter in southern Idaho.