Help! Fraudulent CS order processing

This is complex so I'll try to do a Reader's Digest version:

1. My son had an on again/off again relationship with a young woman in Washington state.
2. The relationship resulted in a pregnancy and subsequent birth of a child.
3. The child was born during an off again period of the relationship, however, they were somewhat amicable at the time and he was with her for the birth.
4. He as in the process of selling his house and relocating to another state.
5. They were meeting together and hashing out CS arrangements with each other, outside of the court. She told him vehemently that she didn't want the court/state involved.
6. She lied. He was served with papers the day he was loaded and ready to leave the state.
7. Over a period of several months stuff was modified in the court and a lesser CS order was put into place.
8. A few months after that, she relocated with the child to the state where my son had moved.
9. He got an apartment and they moved in together
10. 10 months later they were married.
11. 14 months later they filed for uncontested divorce, my son was named the custodial parent, they had a 50/50 parenting plan in place and CS was mutually waived for a period of 12 months. This is in the settlement paperwork that they both signed and was filed with the court.
12. 11 months later she became a danger to the child and my son had to file an ex parte motion suspending the 50/50 parenting plan. She contested. Supervised only was ordered for her until the contested hearing that would happen after the parenting evaluation. That was 13 months ago. The parenting evaluation was long and drawn out because she was not coopering with the evaluator and in the end her behaviors that precipitated the original ex parte motion escalated and the evaluator recommended supervised visitation until she was successfully treated for her behaviors. (The new proposed parenting plan has been submitted to the court, the hearing has not yet been scheduled but probably won't happen until late spring or early summer according to his lawyer, due to the crowded docket)
13. 9 months into the evaluation my son filed for CS from her. It was granted and ordered to begin in Jan 08.
14. In January she fled the state and returned to Washington state.
15. My son has been notified that there is now a CS order in Washington State for him to pay her CS beginning immediately.

She has not paid any CS in this state to him as ordered. My son has 100% custody here. My son is also the official Custodial Parent. The caseworker in Washington has so far not cooperated with my son in his attempts to straighten this out.

He has not yet placed the CS order in this state (for her to pay him) with CSED, it is in the Court of Clerk office as that is the way his attorney wrote the order.

What documentation can he demand from Washington State CSE to substantiate their claim? Isn't this considered fraud? They are asking for all kinds of financial information from him but won't let him send substantiating documents that prove he has legal and physical custody of the child and has had for 2 years. How can Washington order a CP to pay a NCP who doesn't have anything but supervised visitation (and hasn't even exercised that for 60 days) and when there is a current opposite order in the state where the child and CP reside?

You need to get the orders in front of both judges and have one court take jurisdiction on this. They would normally not be doing that if they were informed of the orders in the other state. The first court involved usually keeps jurisdiction unless and until it gives it up.

The original order from '03 in WA was withdrawn, at HER request in Feb '04. She moved to this state in March of '04 and didn't return to WA until Jan '08. According to WA CS office, she still has to prove that she has physical custody (which she doesn't and won't be able to proove). The new state gained jurisdiction when the divorce and orginal parenting plan was signed and filed here. At least that is my understanding since the parenting plan and CS (that was mutually waived for the first 12 months) were filed along with the divorce paperwork.

I am pursuing information about quashing the old '03 order since she has resurrected it.