Adventure Game Studio

I'm not sure how I'm even supposed to go about finding out who stole my wallet. I know it was a guy with a scar on his face that looks a bit like another guy walking around the town, but I can't do anything with that. The police said I should file a report, but when I try it just says "I have nothing else to report"

Talk to the clerk at the impound unit
Talk to the workmen at the roadworks
Talk to the children with the bottle
They should all have partial descriptions of the robber and/or converstaion topics that might trigger the next bit

Also, try examining (right clicking) the fast man with a scar on his face

When you can file a report, you should get a white page with checkboxes, letting you specify his physical characteristics
If you've already done this and you're being told you have "nothing else to report", you don't need to worry -- the police are on the case. Go explore a little more and wait for the robber to go inside the police building.

Also, if you haven't done it, the clerk at the petrol station might have a package he wants you to pick up.

I didn't realise you were able to go in the gas station, which seems to be what triggers most of the gameplay

Were you expecting to steal gas from the pump? (laugh)