As a racial characteristic1
Silent Hunter: Elves are renowned for their subtlety and skill. Elves with this racial trait reduce the penalty for using Stealth while moving by 5 and can make Stealth checks while running at a –20 penalty (this number includes the penalty reduction from this racial trait). This racial trait replaces elven magic.
As a regional trait2
Silent Hunter (Regional): You have served discreetly following interlopers through the twilit city streets to pinpoint their locations for the authorities. You gain a +1 trait bonus on Stealth checks, and Stealth is always a class skill for you.