Investigators are searching for dozens of teens reportedly involved in mob assaults on two consecutive nights in a Southeast Portland park. The Portland Police Bureau reports that a little after 10:30 p.m. Wednesday, responding officers found several groups of teens roaming the park. As they were telling the teens to clear out, a witness directed them to a 14-year-old boy who had sustained facial injuries in an alleged attack. The boy told police that he was with a friend when a group of African American teens approached him, beat him up, and stole his cell phone, iPod, headphones and hat....