Is it a crime to not pay a contractor bill?

The best answer is "it depends."  At first blush, this looks live a civil suit.  The remedy is to file a lawsuit or place a lien on the home.  A good number of businesses have been plagued with clients that fail to pay as the economy tumbled.  Most are considered civil matters.  However, there may be a criminal offense called "theft of services" or "theft by deception."  Texas recognizes several different types of thefts.  If your husband was contracted to complete a job, was told payment would be made in full upon completion, and the client represented that they had funds sufficient to make that payment, when in fact they did not.... then they induced a service by a false representation.   These type of facts could support a criminal charge.  If the client paid some, but missed a majority of payments, the case would lean back tot he civil side because the attempts at payment would negate or rebut their specific intent to commit theft.  Other factors could make this more of a civil than criminal matter, or vice versa.  It doesn't cost anything to file complaint with the police, but you should still consult with an attorney about filing a suit for damages to perfect your husband's lien-- the police cannot do this for you.  Your best bet of getting your money back to essentially to hold their house hostage with a lien.  If there are several fraudulent overtones, an attorney can also help you file the complaint with the police so that you are leveraging all of your available resources for recovering the $15,000.00.