violent roommate. what should i do.

ok this is kind of a long story. first i got taken out of college due to money issues and i ended up homeless for a while. one of my friends who id known for a year suggested that i get an apartment with him and everything would be fine. wrong. i ended upi having to invest about twice as much money into the apartment than he did. he took the master bedroom and had me sleep in the floor of the closet space known as the second bedroom. then i found out he was an avid pot smoker. from morning toil night that was all he did was go into his room and smoke, and soon our entire apartment began to smell of pot. we were never around each other so we would write each other notes reminding each other of what to do while we were gone. everytime i would ask him to do something, like asking him to at least spray some airfreshener every once in a while, he would leave note upon note upon note telling me off and cussing me out and telling me i was a horrible roommate. i enbded up having to go to the cops once to report him smoking and they said they couldnt do anything because of the fact that it was a private residence and he would only smoke in his room. if he had smoked in a public area like the living room all i had to do was call them and he was busted, but he never left his room. eventually it got to where he was using my bath supplies instead of his own. when i asked him to stop he freaked out, verbally attacked me and tried to convince me that someone was breaking in to use our shower while we were away. then things got bad. so bad to a point where he broke our kitchen window with his fist and tried to convince me he accidentally did it with and airsoft gun. then he stole my car to go on a drug run. and tried to tell me the keys magically appeared on his bedspread. eventually things calmed down for a while. but after all this i heard him and some of his friends talking mess about me, calling me dumb fat ugly and stupid. his friends have never met me before. i kicked out his friends and told him to never talk behind my back and if he had something to say to me, he could be an adult and say it to my face. then things got worse. because i had called him out he began harrassing me with notes and began texting me at work, telling me i was the worst person in the world and i was better off dead. how nobody liked me and my personality (even though i was never at home enough for him to know) was annoying to everyone around me. he threatened to wreck the furniture i bought for the livingroom. (keep in mind in this apartment i had to contribute everything to the household. even groceries) and eventually he came in one night and verbally attacked me in the livingroom. then marched upstairs and began throwing things and wrecking the upstairs area. i feel threatened for my personal safety. i went to the police and filed a report because things are only getting worse the more i live with him. i am very certain that it will get physical soon. the police said all i have to do is sign the warrant and he will be arrested. after the visit with the cops i also found out that hes doing more than just smoking pot. what other drug he might be doing. i have no clue. but as it turns out, he told me he was a college student. the police did research on him and found out he was no longer a student anywhere. he doesnt have a car but hes constantly going onto campus nearby and never comes back until late. ive already talked to the landlord about trying to get him out of the apartment and i showed him the police report as proof of my fear for well being. the landlord refused to do anyting but call my roomate to let him know about me filing the report, which is making things worse. i haven been back home in two weeks for fear of getting hurt. should i sign the warrant. if i do and he gets arrested, one of his friends will bail him out and he would probably come straight for me. should i just get a small loan, pack my things and get out. i have so many thoughts in my head on what i can do that im confusing myself. please help.
i dont have anyone else that rooms with me and my roommate has already told me he refuses to move out and the land lord isnt doing anything about it.