What is this brown spider with black and white stripes? (Atlanta, Georgia)
It resembles Dolomedes tenebrosus, commonly called the Dark Fishing Spider, and it belongs to the family Pisauridae.



Image Source: Bug Guide

Males are generally thinner in profile than the females, which is well depicted below.



Image Source: Spiders.Us

Based on the pictures provided, you seem to have captured a male Dolomedes tenebrosus.