Based on the true life experiences of poet Jimmy Santiago Baca, the film focuses on half-brothers Paco and Cruz, and their bi-racial cousin Miklo. It opens in 1972, as the three are members of an East L.A. gang known as the "Vatos Locos", and the story focuses on how a violent crime and the influence of narcotics alter their lives. Miklo is incarcerated and sent to San Quentin, where he makes a "home" for himself. Cruz becomes an exceptional artist, but a heroin addiction overcomes him with tragic results. Paco becomes a cop and an enemy to his "carnal", Miklo.

As a young man, Montoya Santana (Edward James Olmos) is introduced to gang life on the tough streets of Los Angeles after spending his youth in reform school. Soon Santana finds himself facing an 18-year prison sentence. In jail, he works his way to the top of the institution's violent drug trade, but, on his release from prison, he opts for a redemptive, family-centered lifestyle. However, his gangster friends (Pepe Serna, William Forsythe) try to force him back into illegal activities.

After growing up in the gang lifestyle of the Los Angeles projects, 18-year-old Caine Lawson (Tyrin Turner) wants a way out. Everyone around him, including his unpredictable friend O-Dog (Larenz Tate), is trapped in their lives of crime and violence. With the help of his caring teacher (Charles Dutton) and supportive girlfriend (Jada Pinkett), Caine plans to leave the city for good. But in a series of tragic events, Caine realizes that escape will not be easy.

In this gritty police drama from director Dennis Hopper, street-wise cop Bob Hodges (Robert Duvall) and hotheaded rookie Danny McGavin (Sean Penn) grapple with their new partnership on the gang-ridden streets of Los Angeles. Although Danny finally lets Hodges show him the ropes, his adrenaline-fed brutality earns him a reputation with the very gangs they want to help. With a gang war ready to explode, Danny confronts his own racism even as he falls in love with Louisa (Maria Conchita Alonso).

When a student writes the police code for homicide, 187, inside a textbook owned by teacher Trevor Garfield (Samuel L. Jackson), he feels threatened. The principal dismisses the incident, but, soon after, Trevor is stabbed by the same student. Fifteen months later, a physically and emotionally scarred Trevor relocates to California and takes up substitute teaching. To his dismay, his new school is as full of dangerously undisciplined students as the last one, driving Trevor over the edge.