NASHVILLE, Tenn. -- Four people were killed and several others were wounded in a shooting at a Waffle House in Tennessee early Sunday, authorities said. The Metropolitan Nashville Police Department identified the suspect as 29-year-old Travis Reinking of Morton, Illinois, who remains at large.

Reinking arrived at the Waffle House parking lot in Antioch around 3 a.m. local time. He exited his truck and began firing an AR-15 at two people outside the restaurant, Nashville Police spokesman Don Aaron said. He then went inside the restaurant and opened fire.

Authorities discovered two magazines of AR-15 ammunition in a green jacket Reinking left behind. "He clearly came armed with a lot of firepower to devastate the south Nashville area," Aaron said.

Get Breaking News Delivered to Your Inbox

"There is a chance that Reinking is at large with two other weapons," he added. Police said they were not aware of any motives for the shooting.

"We suspect some mental issues but at this time there's no notes, no verbal explanations so we don't have a motive at this time," Nashville Police Chief Steve Anderson said in a news conference Sunday.

Travis Reinking Metro Nashville Police Dept.

Shooting victims identified

Authorities identified the victims as 29-year-old restaurant worker Taurean C. Sanderlin of Goodlettsville, 20-year-old restaurant customer Joe R. Perez of Nashville, 21-year-old DeEbony Groves of Gallatin and 23-year-old Akilah DaSilva of Antioch.

Two patients were receiving care at Vanderbilt University Medical Center on Sunday, one was listed in critical condition and the other in stable.

Dasilva's mother, Shaundelle Brooks, told CBS News her son was a student at Middle Tennessee State University where he pursued a career in musical engineering.

"He meant the world us. He was humble, kind, compassionate, outgoing and very creative. We could describe him in so many words. He spoke through his creativity and he entertained the world through his music," she said. "Akilah ... meaning the intelligent one who reasons."

The family said his girlfriend, 21-year-old Shanita Waggoner, was one of those wounded in the shooting. They said she underwent surgery and doctors were "trying to save her leg."

Metro Davidson County Police inspect the scene of a fatal shooting at a Waffle House restaurant near Nashville, Tennessee, on Sun., April 22, 2018. Reuters

Waffle House "hero" James Shaw Jr.

Police praised a customer who prevented further bloodshed in the shooting. They said James Shaw Jr., 29, rushed Reinking, wrestled him to the ground and tossed the weapon. Shaw's hands were severely burned from grabbing the AR-15 but he still managed to push Reinking out of the establishment.

"He is the hero here, and no doubt he saved many lives by wrestling the gun away and then tossing it over the counter, and prompting the man to leave," Aaron said.

Shaw said he wasn't going to make it easy for Reinking to kill him and said he knew he only had one chance.

"I saw an opportunity -- my window -- so I took it. I ran through the door as fast as I could and just kind of jammed him up with the gun when it pointed down. We started wrestling and fighting for it. I just took it and tossed it over the counter. I pushed him out of the restaurant and he walked off," Shaw told WTVF-TV.

Shooting suspect's past

In July 2017, Reinking was arrested by U.S. Secret Service for being in a restrictive area near the White House. Special Agent Todd Hudson said Reinking had refused to leave the area, saying he wanted to set up a meeting with President Trump.

Reinking's firearms authorization was revoked in Illinois and four weapons were seized by authorities, among them was the AR-15 used in Sunday's shooting, police said. The guns were returned to Reinking's father, who told police he gave them back to his son.

Police said they discovered two guns, but two others were still unaccounted for.

Reinking was added to the Tennessee Bureau of Investigation's (TBI) "Top Ten Most Wanted list" and authorities are offering a reward of up to $2,500 for information leading to his arrest

The weapon used in Sunday's shooting. Metro Nashville Police Department

Witnesses recall shooting

A witness, Chuck Cordero, said he watched the gunman shoot his friend, who works as a cook at the restaurant.

"He pulled up, he got right out, he was prepared to do what he did. He didn't look around for anybody, he just kinda got out and just started shooting and there just happened to be two people standing right outside," Cordero told WTVF-TV.

Another witness, BJ McMurry, was inside the restaurant during the shooting. He said the "number one thing I could think about was calling my wife and my son."

"I don't think I've ever seen someone there like that -- someone lying on the floor bleeding and there's nothing you can do," McMurry told WTVF-TV.

Waffle House issued a statement saying they were "deeply saddened" by the "tragic incident."

"This is a very sad day for the Waffle House family, and we ask for everyone to keep the victims and their families in their thoughts and prayers," according to the statement.

As the manhunt continues for Reinking, Nashville officials announced on Facebook that schools in the search area will follow "lock out procedures." They explained that "students will be free to move throughout the building as usual, however there will be no guests or visitors allowed to enter the building":

We want to provide important information regarding our plans for school tomorrow (April 23) in light of the ongoing... Posted by Metro Nashville Public Schools on Sunday, April 22, 2018

CBS News' Gisela Perez contributed to this report.