Robomuggers

It's interesting that you and Helix both saw the same thing. What type of robot is Helix?

Medium duty warehouse robot, Serial Number 1890-1938.

You didn't look at him.

No need. His radio transponder told me what and where he is.

So if a robot was using a transponder other than his own…

GREAT TURING'S GHOST! No wonder we can't find these muggers! They're in disguise!

1890-1938 – the years of life of the famous Czech writer Karel Čapek, co-author of the word “robot” (second co-author - his brother Josef)
Alan Turing – A renowned expert in automata theory related to research into artificial intelligence and in particular the distinction between humans and machines (the inverse Turing test, aka “captcha”)