Mark of Truth

Enchantment Tier: 3 Components: Verbal, Somatic Casting Time: 1 round Range: 40 ft Target: One creature Duration: 1 minute/level Saving Throw: Spell negates Your captive flinches as the mark appears on his forehead. You begin by asking his name.

This spell places a mark upon a creature which compels it to tell the truth. Only you can see the mark. While this spell is in effect, the subject cannot knowingly lie. This spell does not compel a creature to speak, but a character who attempts to lie will always tell the truth. 

A creature can still mislead you by omitting facts.