In 1995, Vélez landed her first major television role as Nina Moreno, a policewoman, in the TV series "New York Undercover". That year, she also made her film debut as Lisette Linares in the movie "I Like It Like That" alongside Rita Moreno and Jon Seda. She was nominated for the Independent Spirit Award and The Desi Award for Best Lead Actress. The movie was nominated for four Independent Spirit Awards and won an NYFCCA award. Another TV series in which she performed was HBO's jail drama "Oz". She also acted in the feature film "City Hall" (1996) with Al Pacino. In 1997, she starred in "Buscando un Sueño" ("In Search of a Dream"), the first Spanish-language film sanctioned by SAG. She again played police lieutenant María LaGuerta, in a major supporting role on Showtime's series "Dexter".