What should I do if something valueble is missing from my room after two guest leave?

I had two guest over yesterday and after they left I noticed a valuable ring was missing. I called her immediately and sent txt messages with no results. I’ve also herd they have theft priors and I figure they probably sold it to a local gold buyer. So Im wondering if file a police report now or would that be a waste of time? Or should I just take up matters in my own hands? Any advice would be great. Thanks.