This has probably been done to death...
Is there a pen on the market, of the click ball point
type, which is actually a spike, a stabbing weapon?
If you were searched, what's the chance this would
pass, if the spike was not exposed?
And how about a ring, with a cap (looks like a class
ring maybe), spring open the cap, it exposes a
spike? Is that strictly James Bond? Of course it
would be very short, like a thumb tack, but still