If you can prove that the properties are yours, you likely can call the police.
The police likely will eventually give you back the properties after confirming that you are the rightful owner and the criminal law case against the thief is done.
If the thief is convicted, the thief can be in prison for many years depending on the value of the properties taken and the criminal law history of the thief.
You can also sue the thief directly, perhaps through the procedures in Chapter 7.64 RCW (REPLEVIN).
Reporting to the police may better safeguard the properties since the police may be able to immediately seize the properties. Being sued in civil court may give the thief time to dispose of the properties.