littledetective:

“You know, I have half-a-mind to find you
   now and see if this ‘phone dying when I’m
   around thing’ actually works.” He plucked
   the card up and looked it over, then
   scowled at the transmitter.

He had to be close enough to shoot this thing
   accurately, but he couldn’t find him from
   where he was standing now. Dammit.

And good luck trying to find him. He’s in his ‘incognito’ clothes right now, and he sure as heck wasn’t staying near after getting the card in place, so he just casually wandered off like any other random passerby. Didn’t want to test how close he’d have to be for it to take effect, so he’ll stick with his safety of ‘card shot’ distance and then stay in range for the transmitter to work.

The thief does know how not to bring attention to himself. Sometimes.

“Oi, oi… Give me a break, it’s not like I use my phone to just help me steal things. I do have a more normal life I’d like it to be working in, too. I doubt you’d be happy to get phone troubles, hmm, tantei-kun?”