'Prison Break' actor joins 'True Blood'

Marshall By Nellie Andreeva

Marshall Allman is joining the cast of HBO's "True Blood" as aregular for the upcoming third season.

On Alan Ball's vampire drama, Allman will play Tommy Mickens, SamMerlotte's (Sam Trammell) long-lost younger brother who works at aTire Depot in Arkansas.

Allman, who was a series regular on Fox's "Prison Break" playing LJBurrows, recently guest-starred on AMC's "Mad Men" and FX's "It'sAlways Sunny in Philadelphia." The actor, whose feature credits include "The Immaculate Conceptionof Little Dizzle," is repped by Gersh.