How do I amend my divorce petition in the state of Washington to include desertion and bigamy?

1. If he was married to another woman when he married you, your action is not for dissolution of marriage but for a declaration of invalidity. You may need to amend your Petition accordingly, and have him served. 2. Desertion is not part of either action: dissolution or declaration of invalidity. You can raise it in a motion for temporary orders, or in support of your final orders eventually, but it is not relevant to your petition. 3. How to amend your petition? Look on the courts' website of mandatory forms (www.courts.wa.gov/forms) for the Petition for Declaration of Invalidity. Compare it with your dissolution petition. If he has not yet filed a response to your petition, file your amended petition with the Clerk, and have him personally served with the amended petition. This will probably involve some procedural hurdles along the way, and it sounds as if there may be some other significant issues. You should seriously consider consulting an experienced family law attorney for help.