Police don't believe the victim has any gang affiliation.
The Tri-City Herald reports he was beaten Jan. 11 at the Keewaydin branch of Mid-Columbia Libraries. His laptop fell during the assault and was taken by three teens who fled.
The victim required six stitches for a head wound.
Detectives arrested 17-year-old Cyril Vaughan who has pleaded not guilty in Benton County Superior Court to a robbery charge.