I offer to do all debt collections in the USA for 15%+ any expenses, I know where he is and where his family lives.
I have already pulled his background check and other information.
This guy seems like your best bet.
Yes... Your best bet if you had proof...
A debt collector can't collect debt if there's no debt to collect.
You haven't posted any proof that you - a) helped him and b) agreed a fee should you fulfil what you both agreed on - in other words, whatever was written on the contract.