Pretty much anything that results in resolution of an internal case should lead to the gift card reward.I kind of lean toward this. My rules for reporting are if it hurts the store I will report it. If it's something like this, I figure it's not my issue to fix.
While Target does do cash rewards for catching theft. I am not sure this would qualify so there's a part of me that would wonder what do I benefit for outing someone?
Another note. The store leadership or store AP will not be who actually investigates. This type of activity is handled by corporate with support from the investigation center.