Authorities identified the gunman behind a deadly rampage at a Nevada IHOP as a 32-year-old local man, who opened fire with an AK-47 on five uniformed National Guard members, killing 3 and another person before killing himself.

Police say Eduardo Sencion of Carson City arrived in a minivan registered to his brother, and opened fire at an IHOP restaurant in Nevada's capital city Tuesday, wounding eight people and killing three before fatally shooting himself.

Aside from the AK-47 rifle used in the attack, authorities say they found a pistol and another rifle in the minivan Sencion left in the parking lot.

Carson City Sheriff Kenny Furlong said Sencion was not in the military, had no known ties to anyone in the restaurant and had worked at a family business in South Lake Tahoe. Family members say Sencion had mental issues.

"We came into this with everything we had. All agencies were committed to it," Furlong told the Associated Press. "There were concerns at the onset, so we took certain steps to ensure we had the capability to embrace an even larger circumstance. At this point in time it appears to be isolated to this parking lot."

More On This...

Nevada Governor Brian Sandoval released a statement Tuesday indicating the shooting was an isolated event.

"All reports I've received this afternoon and evening indicate a high level of cooperation and efficiency among all Nevada agencies and their federal counterparts. It appears today's shooting was an isolated incident and I urge Nevadans to focus their thoughts and prayers on the victims of today's tragic incident and their families," he said.

Gilberto Sencion Gonzalez, 46, identified himself as Eduardo's brother and told the Reno Gazette-Journal, "I feel very sorry about what happened."

"I feel very sorry about those people. I'm trying to find out what happened," he said.

Witnesses said a man pulled up in a blue minivan around 9 a.m. at the IHOP restaurant in a strip mall on Carson City's main street. He shot a man on a motorcycle, then walked inside the restaurant and started shooting, said Ralph Swagler, owner of Locals Barbecue in the same strip mall as the IHOP.

Both Guard members killed were men, authorities said.

Swagler told the Reno Gazette-Journal that after several minutes, the man walked outside and began firing into the Locals Barbecue and an H&R Block in the strip mall.

"This happens in third-world countries, not here," Swagler said.

Fran Hunter, who works at Sierra Le Bone, a pet shop just north of the IHOP, told the newspaper that the suspect fired at least two shots toward Casino Fandango across the street.

"I don't know what's happening to my city," Hunter said. "This happens in L.A. or Las Vegas but not here."

Local and state police and FBI agents descended on the scene, and yellow police tape surrounded the parking lot at the restaurant, which is near a Kohl's department store.

Renown Regional Medicare Center spokesman Dan Davis told The Associated Press four victims of the shooting were being treated at the hospital in Reno, but he said he could not discuss their condition or provide any other information.

Kurt Althof, public relations manager for Care Flight, told the Gazette-Journal three victims had been taken to the hospital by helicopter and that two were in critical condition.

Nevada Highway Patrol Trooper Chuck Allen said extra security measures were put in place at state and military buildings in northern Nevada as a safety precaution.

"As you know, when you have people in uniform who are randomly targeted for whatever reason this may have been, it is a safety precaution we take very seriously," Allen said.

Sen. Harry Reid, D-Nev., released a statement expressing condolences to the victims' families.

"I'm deeply saddened by this senseless act and extend my sympathies to those afflicted this morning," Reid said. "I applaud the first responders for their professionalism, and my thoughts are with the victims and their families during this difficult time."

Rep. Joe Heck, R-Nev., posted on Twitter that his heart and prayers go out to the victims' friends and families. And state Sen. Ben Kieckhefer tweeted: "My God be with the families of those hurt and killed in the senseless violence today in Carson City."

Furlong says Sencion was born in Mexico and was in the U.S. under a valid U.S. passport.

The Associated Press contributed to this report