In 1977, Steven landed the role of teen-aged son Joe, on public television's first bilingual sit-com "Que Pasa, U.S.A.?" Three years later, he moved to California and appeared in guest- starring roles on "Hill Street Blues", "The Rockford Files" and "One Day at a Time". Moving to New York, he studied with famed drama coach Stella Adler. Steven appeared in several off-Broadway productions including "Waiting for Lefty", "Mozart and Salieri" and "A Balm in Gilead".

In 1983 he was offered his first big-screen role as Manny Rivera in Brian DePalma’s "Scarface”, for which he received a Golden Globe Award nomination. He followed this with the romantic lead in "Thief of Hearts". His critically acclaimed portrayal of Kiki Camarena in the 1990 Emmy Award- winning television mini-series "Drug Wars: The Camerena Story", earned him his second Golden Globe nomination.

During the 1990's, he had roles in major productions including "Raising Cain" and "Primal Fear". In 2001, the role of Carlos Ayalla won him a Screen Actors Guild Award as a member of the cast of Steven Soderbergh’s "Traffic". Currently, he is married and divides his time between Los Angeles and Miami.