Laws Regarding Property of Deceased Parent

Back taxes can be paid by you as well as back rent. The landlord can put a lien against the trailer for back rent. The trailer could be considered city/county/state property for the taxes not paid. Depending on the time lapse.
See the city office first. You may owe utilities as well if you claim the trailer and belongings.

An tax or estate attorney from Arizona is the best and most accurate source of information that you are seeking. You could also contact people at the town or city hall or the tax department for the state of Arizona.