What are our landlords rights?

What kind of rights do we have as a landlord? In the movie Pacific Heights the landlords really didn’t have any rights at all. The two main characters purchased a triplex in which they would live in one apartment and rent out the other two. The characters seemed to be very precise on how they chose to rent to their potential renters. The movie showed them interviewing and showing numerous renters around. After each of the renters showed interest they asked them to fill out an application so they could do a background check. There were two instances where the renters showed disinterest in filling out the particular forms. The female character stood true to herself when one of the potential renters said they did not want to fill out the application. She stood up to him by saying that it was there rule and that he would have to in order for them to rent to him. He ultimately agreed. The male character encountered the same situation with another potential renter. The problem with him was that he gave into the potential renter and let him not fill out the application.
The renter that did not fill out the application turned out to be a poor choice for a renter. He decided to not pay the landlords and proceeded to wreak havoc on them. There is one scene where he calls the cops on the landlords because the landlord shut off his power and gas the night before. The cops stated to the landlords that it was against the law for them to do that. The landlords really didn’t have any rights at all when it came to this renter. The only thing they could do was to get a lawyer and to go through a long process of eviction.
My feeling on this is that if you own property you should have the right to say what goes on in that property. The only way your right should be taken away is if you have someone sign a contract taking away your rights. The landlords in the movie should be able to throw the renter out without having to go through the eviction process. The renter didn’t sign any written agreement giving him any rights to be there. I think that since he did not sign an agreement that he shouldn’t be allowed to stay.