You can apply for a National Police Certificate (NPC) through the WA Police Force online. You will need to complete a 100-point identity check. 

For international students, a current international passport with a valid Australian visa is worth 70 points, and other documents such as a UWA student ID card, Australian bank statement, proof of lease or an Australian driver’s licence may be used to make up the remaining points. 

Check the full list of accepted documents and apply online through the WA Government National Police Certificate page.