New roommate moves in on November 6th, 2009 to rent a room in a house with 3 other roommates. When asked for the rent on November 8th, 2009 the new roommate says that he left the rent, $600 in cash, on the kitchen table the day before and text messaged another roommate to inform them of the rent being left. The new roommate however didnt leave the rent on the table and lied about text messaging the other roommate.
The new roommate then agreed that he would pay the rent "again" $300 one week and $300 the next week. On the 2nd week that the remainder of the rent was do the new roommate let another roommate know that his playstation was missing from his room. After the new roommate left for work it was discovered that a computer in the living room was also missing.
In the 5 years that the 3 other roommates lived in this house nothing has ever been stolen or gone missing. Money has been left out for days and never been taken.
Please let me know what can be done to remove this new roommate ASAP. The other 3 roommates are in fear that if they leave the house other things will go missing. The new roommate has only been living there for a total of 14 days. What notice needs to be given for the new roommate to vacate the property?

There is no written lease.

Thanks in advance for your help!