Brandon was a drug addict in life, and accrued a laundry list of misdemeanors, as well as several felonies. Barbossa found him during the peak of the Camarilla/Sabbat conflict, while he led a pack in slaughtering a police precinct. Having sated himself on the officers, Barbossa found the mortal locked in a jail cell under protective custody. Barbossa watched the mortal try to assault the bars, screaming for his narcotics. He embraced the mortal and released the raving lunatic into the backwater.
Brandon now maintains a den of junkies that he can feed off of. Where in the backwater this base of operations is located, and which mortals he currently feeds off of, is shrouded in mystery.