The victims were shot in the makeup department at Macy's at Cascade Mall in Burlington, Washington, before 7 p.m. local time, police said.
In addition to the four women who died earlier, a male sustained who had sustained life-threatening injuries died in a hospital, authorities said.
The male victim with life threatening injuries was airlifted to Harborview Medical Center in Seattle and "most likely will pass away," Sgt. Mark Francis, a public information officer with the Washington State Patrol, said during a press conference Friday night. Harborview spokeswoman Susan Gregg confirmed the male victim arrived at the facility in critical condition via airlift around 9:30 p.m., adding "we are not expecting any others."
Police initially said four people were dead, but then revised the figure to three, before updating it back to four fatalities. And police initially said one female sustained non-life threatening injuries, but that was incorrect. Francis said the numbers fluctuated as authorities searched the mall.
Francis described the "one lone shooter" as a "Hispanic male wearing grey," who was last seen walking toward Interstate 5. His motive is unknown.
A helicopter, search teams and K-9 units scoured the area around the mall for the suspect.
Sgt. Francis tweeted a photo of the suspect, writing "Here is the shooter. We believe just one shooter ... Armed with rifle."
Govenor Jay Inslee said in a statement released Friday night, "We urge residents to heed all safety and detour warnings. Stay close to your friends and loved ones as we await more information and, hopefully, news of the suspect's capture."
Mall employees and shoppers hid in stores and fitting rooms.
"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," Armando Patino, who was working the T-Mobile store, told ABC affiliate KOMO. "I hear one shot and then stand kinda still and like two three other people start running out saying gun."
Patino added, "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."
Stephanie Bose, an assistant general manager at Johnny Carino's Italian restaurant near Macy's store at the mall, told The Associated Press she immediately locked the doors to the restaurant after hearing about the shooting from an employee's boyfriend.
"He was trying to go to the mall and people were screaming," she said. "It was frantic."
And Tari Caswell, a shopper in the Macy's women's dressing room told the Skagit Valley Herald she heard "what sounded like four balloons popping,"
She added, "Then I heard seven or eight more, and I just stayed quiet in the dressing room because it just didn't feel right. 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."
Law enforcement officers performed an initial sweep of the mall to ensure it had been evacuated, followed by a secondary search.
Sgt. Francis said police began receiving calls of an active shooter before 7 p.m.
In addition to state and local law enforcement, both the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives have also responded to the shooting.
The FBI tweeted it has "no information to suggest additional attacks planned in WA state."
This is a developing story. Stay with abc13.com for the latest.