Police say the victim parked his scooter around 8:30 p.m. Saturday on the north side of Chicago Avenue across from [Northwestern University’s] Wieboldt Hall when up to 20 males approached him. One of them threw a baseball at the victim’s face and knocked him to the ground, according to an alert from the university. Several others from the group punched and hit him several times. The victim tried to protect himself and fought back. The group eventually fled eastbound toward the lake.