Sergeant Mark Francis of the Washington State Patrol tweeted a picture of the suspect, whom he named as Arcan Cetin, a resident of the city of Oak Harbor.

Local broadcaster K5 said the suspect had been in possession of three guns on Friday night when the shooting took place at the Cascade Mall in Burlington in the US state of Washington.

It also said his ex-girlfriend had previously worked at a Macy's department store where the attack was carried out.

On Saturday, police circulated several images from a surveillance camera showing a man with dark hair in a black, short-sleeved shirt, shorts and shoes entering the mall empty-handed on Friday evening, then later brandishing a rifle in the department store.

Four women died at the scene of the shooting, and a man died from his wounds after being rushed to Skagit Valley Hospital. Police said the ages of the victims ranged from a teenager to a senior citizen.

Hayley Thompson, the Skagit County coroner, said the victims would be identified only after she examined their bodies at the hospital.

But one victim was identified by family members as 16-year-old Sarai Lara, a high school student who had survived cancer as a young girl.

Her sister, Evangelina Lara, told The Seattle Times the teenager had been pronounced dead by police at 2am on Saturday.

The fifth mass shooting in Washington this year sent shoppers running out of the mall and plunged a small town into grief.

Burlington sits between Seattle and Vancouver, Canada, near the border. Its population is about 8500 - 62 per cent white, 29 per cent Hispanic - and the median household income is significantly lower than the state average. The nearest city is Mount Vernon.

"There are people waking up this morning, and their world has changed forever," Burlington Mayor Steve Sexton said at a news conference.

"This was a senseless act. It was the world knocking on our doorstep, and it came to our little community here."

Mr Sexton said he was aching for the moment when authorities "bring this son of a bitch to justice".

An FBI spokesman said on Saturday that although the bureau could not rule out terrorism as a motive for the shooting, there was no evidence to suggest that it was.

Oscar Garcia, a resident of Mount Vernon, said the youngest victim was a girl who was in the make-up department of Macy's with her mother when the gunman approached.

Police did not confirm that account. Mr Garcia, who described himself as a family friend of about four years, said he spoke to the father.

"He's devastated," Mr Garcia said. "When I talked to him, he was waiting to go see his daughter."

The girl attended Conway Middle School and is thought to be the youngest victim.

Burlington residents gathered at a local park to pray and honour the victims.

The Reverend Ron Deegan, who said that he and his wife were at the movies inside the mall when the shooting occurred, was among them.

Five minutes into the film, police stepped in and ushered everyone out of the theatre, said Mr Deegan, who serves as a pastor at three local churches.

The granddaughter of a member of one of those churches was working at a beauty salon in the mall.

Workers there herded customers into a restroom when the shooting started.

"Looking beneath the door, they said they saw male shoes go by and they held their breath," Mr Deegan said.

When police arrived to let them out, several patrons fled with rollers and other products in their hair.

Shoppers who spoke to local media outlets told similar stories of a chaotic scene that followed gunshots in a mall that includes a 14-screen AMC movie theatre, Chuck E. Cheese's and the Children's Museum of Skagit County.

"Someone ran by and said, 'There's an active shooter in the mall' and told us to lock our gate," Doc Barron, who had been teaching a boxing class at the mall, told the Skagit Valley Herald.

Tari Caswell said she was in a women's dressing room at Macy's when she heard "what sounded like four balloons popping, and I thought that was strange because I hadn't seen any balloons", the newspaper reported.

"Then I heard seven or eight more, and I just stayed quiet in the dressing room because it just didn't feel right," she said.

"And it got very quiet. And then I heard a lady yelling for help, and a man came and got me and another lady, and we ran out of the store."

Armando Patino told KOMO News that he helped frightened shoppers hide inside the T-Mobile store where he worked after people began realising there was a gunman in their midst.

"Out of nowhere I just hear somebody yell, and then after that, I turn around and just look at the Macy's and I just hear shots," Mr Patino told the station.

"I turn around and run to the store. Some people didn't know where to go. I just moved them into the [T-Mobile] store. We went in the back where we have a door and everything, and we just stayed there until they told us to evacuate."

Search teams using a helicopter and K-9 units scoured the area for the shooter, who fled on foot, authorities said.

Police offered a description of the shooter, saying he was possibly Hispanic because of a dark complexion. But there was nothing else to inform that very general description, Lieutenant Chris Cammock of the Mount Vernon Police Department said, and he could be of any ethnicity.

"When he exited the scene, I can't speak to routes and things like that right now," Lieutenant Cammock said. "It would be speculation."

Eleven search teams and two K-9 teams spent several hours clearing and securing the mall. Police said they spent over an hour interviewing more than 20 witnesses at the mall.

"One of the most difficult moments last night was knowing there was family out there worried about their loved ones," Lieutenant Cammock said.

Washington Post

First appeared on SMH