WHAT DOES THE COUNTY ASSESSOR DO?

The Maricopa County Assessor has been in the news because he has been indicted for allegedly running an illegal adoption business.  I don’t have an opinion on the merits of the charges against him.  I can tell you that his alleged crimes have nothing to do with the office to which he was elected. In fact, he was allegedly running the business before he was elected.
What is function of the office to which he was elected, county assessor?  The function of the county assessor is to determine the value of all property in the county for tax purposes.  That’s essentially it.  
Why would someone who is running an allegedly illegal and lucrative business that has nothing to do with property run for the job of county assessor?  I have no idea.