I did work for a client who seemed legit. I worked day and night with him for 30 days.
His check to me returned. He paid menagain and the check returned again. This was few weeks ago, since I have found many more people(including his own lawyers) who remain unpaid by him. He's got default judgements against him--though most people are having a hard time collecting $ despite the judgements.
Most importantly, he has been convicted at least once in past for writing non sufficient funds check.
I am in NYC while he is based in California. How can I try and get a criminal case going against him? Do I goto NYPD? The DA?
Always take a part payment up front before starting work. Between 30% and 50% is a fairly standard and safe amount. Always take another part payment after demonstrating your progress. Ideally upon final delivery the balance to be paid for your work should be less than 30%.
If clients are unhappy about paying you up front, you need to ask yourself why they're unwilling to pay anything to start, when they will be paying $10k to you in the very near future.
If they don't trust you, they'll work with someone else. You need to be able to trust them too, and taking a part payment up front is often the quickest way for you to learn that they are trustworthy.
When a client isn't able to pay, you should try and negotiate payment in full over time. Regular, small payments give them a chance to pay off their other creditors and give you regular indication that they're trying to pay you back.
If they refuse to pay, or miss their regular repayments, don't be afraid to go to a debt collector. Make this clear when you are negotiating the payment schedule. At this stage, any money you can get back (less the often expensive debt collection fees) is a bonus.
Even if the amount is paid back in full, we make it a rule not to work for this client again.
For an amount this large, you should definitely talk to a lawyer. Keep a close eye on your cashflow over the next few months.
Best of luck recovering the payment!