Was the hoodie over his other clothes? Or had he changed. That is one of the key pieces of information, obviously.
Where was he going at 8:30 at night?
What are the chances of two UNRELATED muggings in 2 days in the same neighborhood??
I have two theories.
1. John remembered "about" where he was mugged and went looking for his briefcase.
2. He recognized one of his muggers and was going hunting.
1 & 2. John returned to the "scene of the crime"...and guess who hangs there.