(CNN)- An armed 21-year-old man killed by an officer at a mall in Alabama on Thanksgiving night "likely did not fire" the shots that wounded two people and sent terrified shoppers running for cover, police said Friday.
The shooting at the Riverchase Galleria in Hoover, about 10 miles south of Birmingham, happened Thursday, one of the year's busiest shopping days.
Authorities mistakenly thought Emantic Fitzgerald Bradford Jr. fired the rounds that left an 18-year-old and a 12-year-old hospitalized, Hoover police spokesman Capt. Gregg Rector said in a statement.
Police initially said Bradford opened fire after an altercation with the 18-year-old and an officer fatally shot him as he fled the scene. But late Friday, police changed that story, saying that while Bradford was involved in "some aspect of the altercation" and was armed with a handgun, he likely did not fire the rounds that injured the two others.
"We regret that our initial media release was not totally accurate, but new evidence indicates that it was not," Rector said.
Police: Altercation involved more than 2 people
The error came to light after Jefferson County Sheriff's Office investigators and crime scene experts spoke to witnesses and examined evidence, police said.
"Investigators now believe that more than two individuals were involved in the initial altercation," Rector said. "This information indicates that there is at least one gunman still at large."
The officer involved in the shooting is on administrative leave pending an investigation, police said.
The Jefferson County district attorney informed Hoover police Friday that the Alabama Law Enforcement Agency will take over the lead role in the shooting investigation from the county sheriff's office, Rector said. Hoover police will "assist and cooperate fully" in that inquiry and will "conduct an internal but separate investigation" of the officer-involved shooting, he said.
'Freaking out', then escaping
The shooting at Alabama's largest enclosed mall happened shortly before 10 p.m. (11 p.m. ET) Thursday.
Police do not know how the confrontation began but don't believe the 18-year-old who was hurt was armed, they said. A gunman opened fire, shooting the teenager twice in the torso, according to police.
An armed Hoover police officer who was working security at the mall then confronted an armed man running away from the scene and fatally shot him, authorities said.
A 12-year-old girl described by police as a bystander was shot once, but it's unclear by whom, Rector said. Both of the injured were taken to hospitals.
Witnesses described chaotic scenes when gunshots rang out, with customers screaming and staff working to help people flee or hide.
"They (put) us in supply closets and locked the doors. And then we sat there for five to 10 minutes, all freaking out," Lexie Joyner told CNN affiliate WBRC. "And then they opened the escape-route doors, and we escaped."