Q: How to handle unauthorized guest in the rental house

A: Well, you have hit upon a quagmire here. Much depends upon the exact details, both between him and her and you and him and how long you have known of her having moved in. One main issue will be if there is a landlord-tenant relationship between her and either you or him, or if she is essentially just a guest that is over-staying her welcome and refusing to leave. Only a landlord - be it either you or him or neither - can evict a tenant and it must be by filing in court (the police are unlikely to be willing to remove her as a trespasser, though you can always try). IF there is no landlord-tenant relationship, then she likely needs to be removed by a court order for ejectment rather than eviction. Very similar end goals - have the Sheriff come remove her if she fails to leave pursuant to court Order - but quite different ways legally to go about accomplishing it. An eviction is normally faster and cheaper than an ejectment though the ejectments I have done have never had to actually go to trial (so far at least) and have ended with summary judgments meaning those ejectments can normally be accomplished in 3-5 months instead of a year and are cheaper than having to go to trial though they still will likely run a minimum of $3500-$5500 plus court costs. Evictions instead will normally take 3-4 weeks from start to finish and can run about $1,000 if she does not actively fight, to $3,000-$4,000 if they have to go to a hard fought trial, plus court costs. The sky is the limit on pricing if the fight becomes knock down, drag out, pull out all the stops. Even more so if she files an appeal and it takes years. Now all that said, I have been doing this 24 years and only one case has gone up on appeal and only one case has run more than about $5,500 plus costs; most are much less. There are many possible strategies here as well - you could terminate/evict your tenant and thereby get rid of her as well. If you decided to re-rent to the same tenant, well nothing illegal about that...etc.

All in all, you may want to review everything with a local landlord-tenant attorney to learn your options, potential costs, and to work out a strategy that is likely to be the most effective in your specific situation and the most likely to be as cost effective as possible. This is not a do-it-yourself project!

Good luck.