Bully (2001)

This is the true story of Bobby Kent, a teen bully in the suburban town of Hollywood, Florida. Eventually, his best friend and girlfriend team up with the various other kids that are tired of getting beat up by him. Included in that group are the overweight Lisa Connelly. Together, seven teenagers lure Bobby out, deep into the swamp, promising him sex and drugs and when they get there, they beat him to death with baseball bats....