<P> Actor Theodore Wilson died shortly after filming his scenes in the film . </P> <P> Artist Adan Hernandez was hired to create the paintings the character of Cruz Candelaria was supposed to have painted . All of the paintings that were used in the film were created by him . The mural in the reservoir seen in the film's climax has unfortunately been painted over . Hernandez made a cameo appearance in the film as the drug dealer Gilbert in the art gallery scene . </P> <P> The film was shot in and around Los Angeles and East Los Angeles and inside the walls of San Quentin State Prison . The main character Miklo is sent to San Quentin, where much of the film's plot takes place . Several of the then - inmates appear in the film as extras . In addition, several of the prison staff members also appear as others and some facilitated the production of the film by serving as technical advisors . Many members of the staff were given small lines in the film, with the warden giving an extended cameo in a part that is somewhat integral to the plot . In addition, actor Danny Trejo, who appears in the film as Geronimo, had served time in San Quentin before deciding to become an actor . </P> <P> In addition to prison inmates and staff and artist Hernandez, screenwriter and barrio poet Jimmy Santiago Baca cameos as a prison inmate and member of the La Onda council . </P>

Where was blood in and blood out filmed