According to his own account, the Booty Bandit was frequently called upon to "check" new inmates whom the prison staff had a reason to dislike. Far from being punished, he was given extra food and new tennis shoes for services rendered.
A slender Los Angeles gang member called Eddie Dillard reported to an internal inquiry how he was forced to share the Bandit's cell in 1993 and was raped repeatedly over a 36-hour period. When Dillard screamed for help, saying his life was in danger, the guards ignored him and one laughed in his face.
After years of prevarication, botched investigations and growing public scandal, some kind of justice is at last in motion to respond to the reports of shocking multiple brutality at Corcoran prison - brutality encompassing not just rape, but also systematic beatings of new inmates, staged gladiator- style fights between rival prisoners and the shooting of 50 inmates between 1989 and 1995.
A grand jury, examining the powerful testimony in the Eddie Dillard case, has just indicted five prison guards on charges of conspiracy to rape, an unexpected development since the case had been examined and dropped in the past on much the same evidence. And, following a separate FBI investigation, eight other guards are due to stand trial soon for the murder of Preston Tate, one of seven men felled by automatic gunfire during staged fights in the prison exercise yard.
These breakthroughs for investigators and prisoners' rights groups have had to be extracted like obstinate teeth from a prison establishment that operates under a heavy layer of secrecy, and enjoys considerable support from the state's political hierarchy.
Both Pete Wilson, California's outgoing governor, and Dan Lungren, the state attorney general, now campaigning to take over from Wilson in next month's elections, have faced allegations of staging a cover-up at Corcoran.
The Attorney General's Office launched two investigations into the maximum- security prison in the wake of the FBI probe, and a series of damning articles in the Los Angeles Times. But those investigations turned up next to nothing on the most damaging allegations, and ended up reprimanding just one officer - one of the whistle-blowers who set the investigations in motion.
State authorities claimed they were unable to break through the prison guards' code of silence, but some of their own investigators accused them of deliberate obstruction. This summer, Mr Lungren described insinuations of a whitewash as "a bunch of crap". After the latest indictments, he has been more circumspect, perhaps because of his date with the electorate, describing the guards' behaviour as "completely intolerable".
Corcoran has been a troublesome institution almost from the day it opened in the cotton fields near Fresno in 1988. Offering to house the inmates nobody else wanted - including Charles Manson and Sirhan Sirhan, Bobby Kennedy's assassin - the prison threw sworn enemies together in a so-called Secure Housing Unit.
Explosive confrontations between Crips and Bloods, between the Black Guerrilla Family and the Aryan Brotherhood, quickly led to violence. According to witnesses, the guards would engineer fights and end them by firing bullets from above the yard.
New inmates would be roughed up as they arrived at the gates in shackles. On one occasion, in 1995, several prisoners ended up with broken bones and shorn heads. One former prison guard, known as the Bonecrusher, has described how he would squeeze inmates' necks to the point of strangulation and greet them with: "Welcome to hell."
What makes the scandals at Corcoran particularly shocking is the seeming indifference of California's political leaders.
The prison has barely been mentioned in the campaign between Mr Lungren and his Democratic opponent, Gray Davis. And one of Governor Wilson's recent acts was to award prison guards a 12 per cent pay rise, at a time when other public sector salaries are frozen.
Behind such acts lies a campaign financing imperative: with new prisons springing up, the guards' union has donated more than $5m (pounds 3m) to candidates in the past nine years, $1m of which has gone to Wilson and Lungren.Reuse content