Castillo replaces the slain Rodriguez as head of the OCB. A very taciturn man, Castillo lives a reclusive life outside of work. He was formerly a DEA agent in the Golden Triangle of Southeast Asia during the late 1970s. During his time as an agent, he opposed the CIA in endorsing the trafficking of heroin to finance their overseas operations. Some of Castillo's habits, such as his desk always being free of paperwork and his request that anyone entering his office should knock first, were suggested by Edward James Olmos during filming.