The officer, who shot a black man on Sunday, has been named by Wisconsin’s attorney general.
The shooting has sparked demonstrations, BBC reports.
Rusten Sheskey shot Jacob Blake seven times in the back as he opened the door of his car, Josh Kaul told reporters on Wednesday that officers found a knife in Mr Blake’s car, he added, but no other weapons.
In recent days, the protests which has triggered many reactions from various people, organisations, and notable individuals did not only sparked a wave of protests, but have turned violent.
On arrest so far, a 17-year-old was arrested on Wednesday after two people were killed and another injured amid unrest on Tuesday night.
Meanwhile, there are fears that Mr Blake is dead, but sources disclosed that he is recovering in hospital and is conscious.
Unfortunately, his lawyers fear it will take a “miracle” for him to walk again.