This time, undercover cop Tony Baretta (Robert Blake) goes behind bars to nab a master criminal. Posing as a convict, Baretta blends into the prison population in search of a minor-league jewel thief. His real target, however, is the genius who commandeered a huge jewel theft -- and ordered two brutal murders in the process. Guest stars include future Oscar winner Tommy Lee Jones and soon-to-be CHiPs star Erik Estrada. ~ Hal Erickson, All Movie Guide