Look around for any clues left behind.

You search about where you saw the mystery person for any clue you can find. There's not much to be found; the streets are even unusually clear of litter. The only thing you find of any promise is a single metal...thing. You can't tell what you've found, but it looks like some piece of advanced machinery and it has a tiny logo on it. You manage to match the logo to a local distributor with your amazing search engine skills. Now all you need to do is follow up on that lead.