Eviction- Tenant Guest still at Property after Leasee Moved out

[Maria Miers]

Eviction was filed on the tenant for non payment.  Upon inspection of the property, it was discovered that the tenant had moved out but allowed someone to stay in her unit.  When the PM found the guest inside the unit, the guest told him the tenant of the unit allowed him to stay there until the end of the August.  Is the guest considered to be trespassing? What's the best approach to get him out of the property?  Local police department?  Would I be expected to take him to court for eviction even though I don't have a contract with him?  I get the sense my PM may not have a lot of experience with these situations.  Hoping the collective knowledge in this group can offer some avenues to explore. 

Thanks