Quas, I've also responded in your other thread on whether a paladin can smite someone that he detects as evil. Basically, I'm of the view that a paladin who has detected evil on a creature should neither ignore it or start attacking immediately. Rather, he should first try to find out what it has done to have "earned" its evil aura, and what further evil it may be planning. Once he has establised whatever facts he can, he is then free to decide whether to attack it, arrest it, redeem it, or run to warn others and get reinforcements. Of course, if the evil creature attacks him first, he's got every right to defend himself.