If he paid with credit card that may be one way, but other then that not really. If he didn't pay with credit card, and doesn't want to be found, then he probably didn't check in using his real name.

Sounds to me that he doesn't want to be found, and if he's not underage, then it's his right to stay that way. If he is underage, it's doubtful most hotels would let him check in anyways.