When an inmate who is not black enters Will Williams' cell for the first time at San Quentin State Prison in Northern California, one of the last forms of legalized segregation will come to an end.
In a case that went as high as the U.S. Supreme Court, California's prisons must begin racially integrating their cells this month. Integration goes against an unwritten code of conduct among San Quentin inmates, which says they must never communicate with other races.
Click here to listen to a radio report by ABC News' Alex Stone about the San Quentin integration.
Inmates and guards admit they are nervous about the changes because so much of the violence inside the walls of the prison, which sits on the rocky shore of the San Francisco Bay, is caused by racial tensions.
"I just don't think it's going to really work because everybody is so against it," said Williams, who has been locked up at San Quentin for 35 years on a kidnapping and robbery conviction. "The whites are saying they don't want blacks, and the blacks are saying they don't want whites."
Until now, most California prisons, including San Quentin, have been segregated in order to keep the peace. Guards say nearly every inmate in the prison is in a gang. The gangs only recruit their own races, and when the races meet it can often result in deadly violence.
It is hard for outsiders to understand the gang lifestyle inside the prisons.
"We have the whites and they're not even allowed to talk to blacks," said Officer Jamie Allejos, who watches over inmates in San Quentin's B Block. "We've got guys who get beat up just for talking to another race or sharing food with another inmate."
The integration is the result of a 1995 lawsuit filed by a black inmate in California who claimed being segregated infringed upon his rights. The case eventually made its way to the U.S. Supreme Court, which handed it down to a federal mediation court. Both sides agreed to integrate the cells.
Allejos made it very clear that he believes integrating the cells will lead to increased violence.
"The guys who are making these decisions don't know nothing about prison. I think the people who are making these decisions should come here for six months and find out the conditions in here," Allejos said.
Some California prisons will begin integrating this month, but the races will not be fully integrated inside San Quentin until next year because racial issues are so complex at the prison housing California's only death row.
On the fourth floor of one of the prison's cell blocks, Scott Williams, who is known to inmates and guards as "Speedy," studies his law books alone in a cell. Williams used to be what other inmates have dubbed a "shot caller" -- essentially a gang leader who directs members of the Aryan Brotherhood. Guards claim Williams has killed two inmates himself.
Speaking through bars and fencing, Williams explained to ABC News how he would have directed his members to attack other races if they were ever put in the same cell.
"There's many rules that people have to follow in prison, and to integrate these people who have been fighting each other for so long is going to be an extreme problem," Williams said.
Despite the negative views about integration among some inmates and guards, experts point to Texas as an example of where the practice has been successful. That state's prisons integrated in the 1990s and, in time, violence was reduced within the lockups.