Will you take the bag?

You are out late this night. There is a lot on your mind and you have wandered a few miles from your house. The dimly lit suburban street you are on now is unknown to you and seems deserted. You have not seen a soul since you nodded to a dog walker three blocks away.

Suddenly a dark BMW 320i races around a cornor in front of you. Inside you can see 3 people in ski masks. You are in the shadows and unsure if they have seen you. After they pass you they throw a plastic bag out the car window and it lands in some bushes by the sidewalk.

The car disapears down the street, but shortly after a red Ford Explorer follows. It looks like the two people inside is in some sort of uniform. They don't seem to notice you.

You stand around for a minute unsure what to do. Everything is dark and quiet. You walk over to the bag, bend down and look inside. You see a notebook, an old Nokia 3310 and a small pink velvet pouch inside the plastic bag. You open the pouch and see what looks like quite a few sparkling red gemstones.

You look up just in time to see a small light go out in a window across the street. You never noticed the light in the first place. Everything still seems dark and quiet.

What do you do?