I hope this message finds you well, present circumstances excluded. The county prosecutor could not be more wrong relative to this issue in my legal opinion. You have at least two separate criminal violations in play here. They are criminal fraud and writing bad checks...both punishable criminal offenses.
Ohio Code Section 2913.01 is the statute that addresses criminal fraud. It states, in part:
(A) "Deception" means knowingly deceiving another or causing another to be deceived by any false or misleading representation, by withholding information, by preventing another from acquiring information, or by any other conduct, act, or omission that creates, confirms, or perpetuates a false impression in another, including a false impression as to law, value, state of mind, or other objective or subjective fact.
(B) "Defraud" means to knowingly obtain, by deception, some benefit for oneself or another, or to knowingly cause, by deception, some detriment to another.
(C) "Deprive" means to do any of the following:
(1) Withhold property of another permanently, or for a period that appropriates a substantial portion of its value or use, or with purpose to restore it only upon payment of a reward or other consideration;
(2) Dispose of property so as to make it unlikely that the owner will recover it;
(3) Accept, use, or appropriate money, property, or services, with purpose not to give proper consideration in return for the money, property, or services, and without reasonable justification or excuse for not giving proper consideration.
Ohio Code Section 29113.11 covers bad checks, and states in part:
B) No person, with purpose to defraud, shall issue or transfer or cause to be issued or transferred a check or other negotiable instrument, knowing that it will be dishonored or knowing that a person has ordered or will order stop payment on the check or other negotiable instrument.
In the case of criminal fraud, if a person is 65 years of age or older, the penalties for conviction an be enhanced.
While the county prosecutor is correct that this could also be a civil matter, it is by no means strictly a civil matter. Moreover, due to the nature and value at stack here, this is a felony criminal case in addition to being a civil case.
I suggest you contact the Elder Abuse Section of the Ohio Attorney General's Office about this issue as soon as possible. Here is a link to their website: http://ohioattorneygeneral.gov/ElderAbuse
They should be able to help you from both a criminal and civil perspective. To that end, the criminal court can issue fines equal to or greater than that which was misappropriated from you upon these individuals that will be payable to you.
Let me know if you have any additional questions or comments.
Best wishes going forward!