Most likely this is a civil case. Your father should consider filing for bankruptcy or trying to work out arrangements with the debtors. It would be a criminal matter if your dad had the specific intention of stealing money from these two people. That doesn't sound like the case here.
Yes, I agree with the answer given by Mr. Morales.
Michael E. Hendrickson
Attoreny & Counsellor at Law
211 North Union Street suite 100
Alexandria, Virginia 22314
Based on what you have posted it sounds like a civil case. However, I am a California attorney so you should seek the consult of an attorney in your area. Good Luck!