on the east coast in massachusetts david lisak an expert on campus rape. the vast majority of sexual assault on college campuses is being perpetrated by serial offenders and they're not mistaken this is not a result of miscommunication and it's not caused by alcohol they are using alcohol very often but they're using alcohol as a weapon in order to get their victims intoxicated to the stream the vulnerable and extremely easy to say. on average each one of the serial rapists is responsible for six rapes during their college years. they like all sex offenders they learn how to identify a vulnerable population. so in a university setting for example of vulnerable population very often means the youngest people on campus freshman. and i think people also underestimate the level of terror that when you have somebody who you thought was well he's just a student i know him he's the guy who invited me to this party he's he's one of us right he's it and all of a sudden this guy is acting in a way that is is terrifying. the other thing is oftentimes these cases get