Out of control freshman on my hands-please help.

I'm an RA in one of the larger dorms at my undergrad alma-mater where I am now enrolled in grad school. I've been an RA for a few years now, long enough for them to start giving me a stipend. I'm a woman and the floor I live on is co-ed.
There is one student in my dorm who is very difficult and reckless. He has issues with both alcohol abuse and managing his sex life. He often stumbles in to the dorm late, even on school nights and vomits either on the bathroom floor or in the hallway. I've seen nearly-empty bottles of Jack Daniels just lying on the floor that I know are his. I am sure that he is not 21; he's only a freshman, so I believe he's 19. One would think that his sloppy-drunkenness would make the young ladies of this college steer clear of him, but unfortunately many of them do not. Based on my interactions with this student and my observations of the women he brings home, I suppose I can see why. He's tall, handsome, looks like he works out, projects a confident aura, always makes eye contact and does not lose it at least when conversing with a female. If I said he has never flirted with me, I'd be lying; if I said I didn't fall for one or two similar guys six or seven years ago, when I was more impressionable, I'd also be lying.

In any case, this student's sexual behavior is even more alarming than his drinking. Many nights, sex-noises can be heard coming from his room, keeping me up, as I live right across from him. I think he sometimes indulges in several sexual partners per night, since sometimes I'll hear the door open, someone walk out and leave the floor, and later, the sex starts up again with I'm pretty sure a different woman. I do know that he has gotten in trouble for his exhibitionism before; he is banned from another dorm entirely for having sex on the couch in the common room area, which he also managed to break. In this dorm, when one student confronted him once, the student responded by taping a used-condom to the other student's doorknob. It was disgusting. I confronted him about it and got really mad, but the little **** was collected and calm about it and denied taping the condom to the other student's door outright. I told campus security and requested he be removed from my dorm. The college already has him on its radar, of course, but decided not to do anything for some inexplicable reason. They did, however, give me access to this student's psychiatric file (yup, he does have one). A high school psychiatrist tentatively diagnosed him with borderline narcissistic personality disorder. He had gone to see this psychiatrist after being caught having an affair with one of his teachers. He comes from a wealthy family although his parents are divorced and his home address was listed as his grandmother's house. He has been to see one of the psychiatrists at this college several times on orders, but he's been evasive and attempted manipulation both times.

Aside from all this though, is, of course, my concern for the girls who fall for him and let themselves be used purely for sex. There are rumors that this student has taken pictures of girls in the act and spread them on social media. I've overheard him talking to male friends (who yes, do drop by, and it's a really bizarre feeling of relief when they do) about how one girl was a "screamer" and another one he "got her to do deep throat" and also how he's "eaten too much pussy this week to still be breathing." These are close to his real words. Given his braggadacio, I suspect he uses his promiscuity as a way to express prowess amongst his male friends, while he simply uses his good looks and charm to seduce and exploit these naive girls to satisfy his idiotic teenage horniness.

So how does one put a stop to this kind of behavior? How do I get this kid the help he needs? Or should I just ask again that he be kicked out of the dorm?