In reply to RobOggie:
Sorry to hear you got mugged. That's really crap.
If you don't have to look smart or you want to avoid looking smart and an over the shoulder tote bag is OK...
...perhaps a Lidl/other insulated chilled food bag?
Zipped top so contents hidden, insulation is a bit of padding. Maybe too much space, but loads of space for other stuff or more padding.
It would look very unlike a laptop bag and unlikely to attract attention of muggers if supermarket branding makes it obviously for groceries compared to something plain black.
Post edited at 12:44