Police confirm 3 deaths, 7 injuries after shooting at Idaho In-N-Out

TWIN FALLS, IDAHO -- Three people were killed and another seven were injured when a gunman opened fire outside an In-N-Out Burger restaurant in Twin Falls, Idaho, on Saturday, authorities told ABC News on Sunday.

The suspected shooter, whom officials identified as 24-year-old Chad Williams, died from an apparent self-inflicted gunshot wound after being confronted by an armed off-duty Idaho state trooper and a private citizen, Twin Falls Police Chief Matthew Hicks said at a news conference on Sunday.

"We believe these actions drove the suspect from the scene and prevented further casualties," Hicks said of the off-duty trooper and private citizen's actions.

Five of the seven injured victims remained hospitalized on Sunday afternoon, including two in critical condition, according to Hicks.

A motive for the shooting remains under investigation. Hicks said the suspected gunman's family members are cooperating with the investigation.

"Their hearts are also broken at this time," Hicks said of Williams' relatives.

Hicks said investigators so far believe that Williams acted alone.

Lynsi Snyder, In-N-Out's president, said in a statement posted on social media that an employee was among those shot and killed.

"In-N-Out will be mourning with the families and praying for them as they tread through a very painful season," she said.

Police responded to a call for shots fired at the In-and-Out Burger on Blue Lakes Boulevard in Twin Falls at 2:29 p.m. on Saturday, according to police.

"A dispatcher could hear screaming and gunshots in the background," Hicks said of the 911 calls that were made.

Hicks described the scene officers encountered at the In-N-Out as "one of the most chaotic instances a law enforcement officer could face in their career."

A large police presence from multiple agencies descended on the scene, authorities said.

The restaurant is located near a busy shopping area, and during a news conference on Saturday evening, Hicks said there were potentially hundreds of people nearby, calling it an "exceptionally chaotic scene."

The area around the In-N-Out and the Twin Falls Visitor Center remained closed on Saturday evening while authorities continued processing the scene, police said.

Police were still interviewing witnesses and asked anyone with information to come forward, Hicks said.

The FBI said it was aware of the situation and offering assistance to local law enforcement, according to an agency spokesman. T

In a statement on social media, Idaho Gov. Brad Little asked for prayers "as law enforcement and first responders respond to an active shooter situation near In-N-Out."

Twin Falls is a city of more than 56,000 people about 128 miles southeast of Boise.

The FBI is asking for anyone with video, audio or still images that may have captured the shooting to submit them here.

ABC News' Bill Hutchinson and Jessica Gorman contributed to this report.

Editor's note: This story has been updated.