Roomate problem

Roomates who are also cosigners on a lease usually presents a very difficult situation when there is a dispute, especially without a seperate agreement between the three of you. You can look at the lease agreement and determine whether the roomate has violated any of the provisions. There is no joing agreement between the three of you to violate either. Additionally, your agreement is with the landlord, with whose consent you will need in order to remove this roomate from the lease. If this roomate's conduct gets more threatening where police action is necessary, you may have some grounds for removing her from the premises, but otherwise... I'm not sure what to tell you. You may want to set up rules which all of you sign and agree to in order to prevent future disputes.