criminal record

So I learned the man I am researching changed his name. Although that could have been done for a myriad of reasons, the family story is that he murdered someone in Zacatecas in the early 1900s. The man even changed his name, from Epifanio Alvarez to Pedro Alvarado.

The question is, how do I go about researching criminal records in that state?

I realize that unless I have the name of the victim, or unless I get lucky with an arrest or court hearing record of the original name of my subject on it, my chances are nil.

Otherwise I need to ponder other reasons for the name change...not uncommon when someone comes to a new country. Thanks.