Four other people, including a Boise police officer, were injured, Lee said at a media briefing.
Officers responded to reports of shots fired around 1:50 p.m. “with reports that at least one person was shot and down,” Lee said.
Shortly after responding, officers found a person matching the suspect’s description and there was an exchange of gunfire that resulted in the officer’s injury.
Lee said the suspect is in custody and police cannot yet speak to motive. Police are sure there was only one shooter involved, Lee said.
Police said they are in the process of notifying family members of the people involved.
Officers were going from one merchant to the next clearing each business, police added.
Lee said most of the mall — which has 153 stores, according to its website — has been cleared.
Idaho Gov. Brad Little said the shooting is “unthinkable” and he was praying for the people who were injured. He said the state was ready help police investigate the shooting.
Lee said a county task force would investigate the officer-involved part of the shooting.