An unlawful detainer action is an eviction action, explains Findlaw. Courts commonly use the term because in an eviction action, a landlord asserts that a tenant is unlawfully using rental property.
To initiate an unlawful detainer action, a landlord must properly serve a termination notice on a tenant, advises Findlaw. If the tenant fails to vacate the rental property, the landlord must file a complaint in the local court and pay a filing fee. Some jurisdictions require the tenant to file an answer to the complaint, while others only require that the tenant attend a hearing. If the tenant fails to answer the complaint or attend the hearing, the court issues a default judgment against him.
A common defense to an unlawful detainer action filed due to a tenant's failure to pay rent is that the property is not habitable, explains Findlaw. Courts may find that a property is inhabitable based on pest infestations, lack of heat, plumbing or electricity, health code violations, or the landlord's failure to maintain the property.
In order to obtain a judgment against a tenant, a landlord must prove the existence of a landlord/tenant relationship, that notice of termination of the relation was properly served, and the landlord is entitled to the property and the unpaid rent, according to Findlaw. After obtaining a judgment, the court clerk issues a writ of execution to be served by the marshal, who removes tenants who fail to vacate the premises by the specified time.