SAN QUENTIN, Calif. - Each time the heavy gates clank shut behind him, prison guard Robert Trono enters a violent realm of men with nothing left to lose.
The 39-year-old sergeant works in a cramped concrete cellblock that houses 85 criminals awaiting execution. It is a place where riot gear, stab-proof vests, biohazard body suits and fear are standard issue.
Trono helps oversee inmates known as the Grade-B condemned, the most dangerous of San Quentin State Prison's 580 death row prisoners. Singled out for their unruly behavior and gang leadership roles and isolated in a three-story building called the Adjustment Center, they are increasingly targeting San Quentin's guards and other staff members for attacks.
Over the past 18 months, officials say, Grade-B inmates have committed 67 attacks. including an attempted stabbing, 15 kicks and five slashings with crude, prison-made knives and razors. One convict sliced an officer's wrists and hands when he reached into the inmate's cell to deliver a food tray. In five other incidents, small arrows fired from makeshift slingshots have lodged in the arms, necks and faces of guards who were not using protective shields.
Inmates say the attacks are a response to provocations by guards.
"Walking those cellblocks requires every bit of your attention, every moment of the day," says Trono. "There's no room to breathe a sigh of relief until you're walking out those doors."
What Trono and others dread most are "gassings," in which prisoners hurl cups filled with feces and urine or blood at the faces of guards. Prison officials report 41 gassing attacks at the Adjustment Center since 1999. After such attacks, officers are tested for the human immunodeficiency virus and hepatitis C.
Prison officials allowed several guards to be interviewed, hoping to publicize a pending amendment to California law that would drop the 63-year-old requirement that male death row inmates be housed only at San Quentin. The amendment would permit moving troublesome convicts to newer, more secure prisons.
The Adjustment Center has always been dangerous, but crowding and tensions between guards and several prison gangs have worsened markedly in recent months, resulting in the unprecedented number of assaults on officers. As a result, the Adjustment Center has emerged as one of the nation's most perilous prisons for guards, because inmates know the system can do virtually nothing more to punish or control them.
"I've been on a lot of death rows, and I've never heard of attacks like this," says Robert Johnson, a professor of justice and social psychology at American University in Washington and the author of two books, "Condemned to Die: Life Under Sentence of Death" and "Death Work: A Study of the Modern Execution Process."
"The general wisdom is that death row dwellers want to appear to be the kind of people you give life in prison rather than the gas chamber, so they're usually well-behaved. But this sounds like an extension of gang mentality. This sounds like chaos."
Guards at San Quentin have confiscated slashing devices fashioned from razor blades smuggled from the inmate shower area and melted into the end of a toothbrush with a cigarette lighter.
They have seen darts made from paper clips, heavy-duty staples pried from cardboard boxes or legal binders and copper wire from a television antenna. Each dart had been filed to a lethal point on the concrete cell floor.
The missiles are often fired from makeshift blowguns made from tightly wound newspapers hardened with dried oatmeal or propelled with elastic bands salvaged from socks or underwear.
Inmates often spread word of attacks to fellow prisoners by attaching notes to lengths of fishing line or dental floss, guards say. Convicts also start fires in their cells by lighting wads of toilet paper twisted into a wick.
As a result, guards walk the cellblock in tactical teams of four, sliding a plastic shield the size of a picture window between them and inmates.
Officers blame the attacks on members of the Mexican Mafia who have demanded to be returned to the main death row population, where inmates are permitted more freedom of movement and visits in which they can embrace relatives.
Along with gangs such as the Crips and the Aryan Brotherhood - which have complained of reduced exercise and visitation rights - they often physically force other inmates to join in the assaults.
Of the Adjustment Center's 85 prisoners, 45 have attempted assaults on staff members, guards say.
Inmate advocates say the majority of death row inmates - 495 men housed elsewhere at San Quentin and 12 women at the Central California Women's Facility at Chowchilla - cause prison officials few problems.
The Adjustment Center violence cuts both ways, the advocates say, pointing to the 1997 case of inmate Sammy Marshall, who died after officers dragged him from his cell and pepper-sprayed him.
Inmate Alfred A. Sandoval, a quadruple murderer who has been housed in the Adjustment Center since 1987, confirmed that guards have been attacked. But he said the assaults were in response to taunts and provocation by officers. He said prison officials routinely ignore convicts' complaints of excessive force.
"Every time we step out of a cell, officers have their batons drawn, shoulder height, with a can of pepper spray in our face," Sandoval says. "The situation has never been this bad in the 14 years I've been here."
The inmate says prison administrators condone racist behavior by Adjustment Center guards, who often tell racist jokes and refer to the cells for Latino prisoners as "jalapeno row." Pepper spray used on Latinos is referred to as "salsa."
Sandoval, who cooperated with lawyers investigating Marshall's death, later got a T-shirt back from the prison laundry with a bull's-eye target drawn on it and the words "one-shot, one-kill pop, control," according to grievances Sandoval lodged against guards.
The Adjustment Center is so unpopular among San Quentin staff members that many veteran officers use union seniority to avoid working there, forcing officials to scramble to fill vacancies.
That leaves the prison's most dangerous inmates overseen by many of its least experienced guards, often those with one or two years' experience, officials say.
Veteran guards say the most successful psychological tools used to keep order among convicts - such as the threat of a transfer to another prison - have failed with Grade-B inmates.
Prison officials have instituted new security measures, including the use of full riot gear. But most guards feel uneasy when they enter the Adjustment Center's doors.
"Just walking in there, you know your chances of being attacked has risen 10 times over compared to the rest of the prison," says Tony Jones, Tony Jones, president of San Quentin's 800-member correctional officers union. "You can feel the eyes of some very dangerous people with nothing else to do but patiently wait for their chance to hurt you.
"And you know that if you work there long enough, something bad is going to happen."