Logic Puzzle!

You know that one logic puzzle with the labrynth guards? Well this is a copypasta of that with a twist, enjoy.

Three guards stand infront of three doors, one is the exit to the building, if you pick the wrong door you are stabbed, One always tells the truth, one always lies, and the 3rd stabs you if you ask questions more than 7 words long, and if you say more than 3 sentences.  What do?

>>10
HURR
I forgot to mention that the judge, who knew each defendant's exact statement, was able to deduce who the spy was. You can't solve this puzzle without knowing that.