Legal Question in Family Law in California

If you are in California, you can always contact the Department of Child Support Services to assist you at no charge.

Was the agreement made a part of an order or divorce judgement? If so, you can turn it over to DCSS as Ms. Ellifritz suggests. That will be a slow process but they are relentless in enforcing existing orders/judgments. Or you can hire an attorney to file an order to show cause why he should not be charged with contempt of court for not complying with the order. If you only have an agreement and no order, and he is hiding money and assets, you will probably need to hire a lawyer to go after him. DCSS can get an order for you, but it will be slow and they are not staffed well enough to go after much in the way of hidden assets and income.