The suspect in a shooting at a Washington state mall that left five dead is in custody, authorities said Saturday.

Washington State Patrol Sgt. Mark Francis identified the suspect via Twitter as 20-year-old Arcan Cetin of Oak Harbor, Wash.

A gunman opened fire at the Cascade Mall in Burlington, Wash., Friday night, killing four females and a male before fleeing. Law enforcement staged a massive search over more than 20 hours for the suspect, initially described by witnesses as a young Hispanic male wearing black.

Canadian border guards were preparing for the possibility the suspect would enter this country. He was last seen near a major freeway less than an hour's drive from the border-crossing into B.C.

Police have not said where he was arrested.

This frame from surveillance video provided by the Washington State Patrol shows the suspect in a shooting rampage that killed five people at the Cascade Mall in Burlington, Wash. (Associated Press)

The first 911 call came in just before 7 p.m. on a busy Friday night at the Cascade Mall: A man with a rifle was shooting at people in the Macy's Department Store.

By the time police arrived moments later, the carnage at the Macy's makeup counter was complete. Four people were dead and the shooter was gone, last seen walking toward Interstate 5. A fifth victim, a man, died in the early morning hours Saturday as police finished sweeping the 434,000-square-foot building.

'A senseless act'

"There are people waking up this morning, and their world has changed forever. The city of Burlington has probably changed forever, but I don't think our way of life needs to change," Burlington Mayor Steve Sexton said Saturday at a news conference. "This was a senseless act. It was the world knocking on our doorstep, and it came into our little community."

As the small city absorbed the tragic news, critical questions remained, including the identity of the shooter and his motive.

The FBI said terrorism was not suspected.

Nick Torset becomes emotional as he kneels after lighting a candle during a prayer service at the Central United Methodist Church in Sedro-Woolley, Wash. (Ted S. Warren/Associated Press)

Surveillance video captured the suspect entering the mall unarmed and then recorded him about 10 minutes later entering the Macy's with a "hunting type" rifle in his hand, Mount Vernon police Lt. Chris Cammock said.

Authorities did not say how the suspect may have obtained the weapon — whether he retrieved it from outside or picked it up in the mall — but they believe he acted alone. The weapon was recovered at the scene.

The identities of the victims — four women who ranged in age from a teenager to a senior citizen — were withheld pending autopsies and notification of family. The identity of the man who was fatally shot was also withheld and may not be released until Monday.

Cancer survivor, 16, among victims

But the Seattle Times reports that one of the victims was a 16-year-old girl.

Sarai Lara's mother said she had survived cancer as a young girl and was a happy student.

Washington State Patrol Sgt. Mark Francis, a public information officer, talks to reporters Saturday at the Cascade Mall in Burlington, Wash. (Ted S. Warren/Associated Press)

Evangelina Lara told the newspaper through a translator that she was shopping Friday night at the Cascade Mall with Sarai and her younger sister, but they split up.

She says Sarai went to Macy's looking for pants. News of the shooting spread through the mall, and Lara tried to get to her daughter but was unable to do so.

Evangelina Lara says it was confirmed at 2 a.m. Saturday that her daughter was among the five people killed.

"Probably one of the most difficult moments for us last night was knowing that there were family members wondering about their loved ones in there," Mount Vernon police Lt. Chris Cammock said.

Massive manhunt

Earlier Saturday as police scrambled to find the shooter, the small city waited and worried.

The community of 8,600 people is too far from Seattle to be a commuter town, but its population swells to 55,000 during the day because of a popular outlet mall, retail stores and other businesses. Burlington is the only major retail center within 48 kilometres in a region where agriculture is king, said Linda Jones, president of the Burlington Chamber of Commerce.

Residents gathered Saturday to comfort each other at a community gathering in a city park.

"It's too scary. It's too close to home," said Maria Elena Vasquez, who attended the gathering with her husband and two young children.

Those who survived were still trying to process what happened as their community became the latest entry on a list of places known by the rest of world for mass shootings.

Rachel Marsh, 15, right, and Selena Orozco, 15, left, light candles as they attend a prayer service for the victims. (Ted S. Warren/Associated Press)

Joanne Burkholder, 19, of nearby Mount Vernon, was watching the movie The Magnificent Seven in the mall's theater when security guards came in and told them to evacuate immediately. Dozens of panicked moviegoers gathered in the hallway, and Burkholder heard screaming as the officers escorted them to safety in a parking lot.

As she drove home later, she had to pull over because she was shaking so hard, she told The Associated Press.

"I'm just very thankful for my life this morning. I've never been so terrified in my life," she said Saturday, trying to hold back tears as she attended the community vigil.

"You'd think it would happen in Everett or Seattle, but a small town of Burlington, I'd never dream something like this would happen."

Candlelight service

People who believed they may have lost loved ones were being sequestered at a church three blocks from the mall, where counselors and a golden retriever therapy dog were present.

Dozens of people attended a Saturday evening prayer service for the victims. The gathering was held at Central United Methodist Church in nearby Sedro-Woolley, Washington.

People fled, customers hid in dressing rooms and employees locked the doors of nearby stores after gunshots rang out just after 7 p.m. Friday at the Cascade Mall. (Dean Rutz/Associated Press)

The Rev. Cody Natland lit five candles on a table in front of the church, one for each victim.

The Cascade Mall is an enclosed shopping mall that opened in 1990. It features J.C. Penney, TJ Maxx, and Macy's stores, among other shops, restaurants and a movie theater.

On Sept. 17, a man stabbed 10 people at a Minnesota mall before being shot and killed by an off-duty police officer. Authorities say Dahir Ahmed Adan, 20, stabbed the people at the Crossroads Center in St. Cloud.