Every 30 minutes, day and night, guards walk the tiers of the isolation unit at California State Prison, Sacramento, checking inmates to make sure they don't kill themselves.

The guards have been doing so since October, when the prison system instituted a series of reforms to cut the high rate of inmate suicides. The steps were prompted by a federal judge's finding that a disproportionate number of suicides occurred in the isolation cells used to segregate inmates for disciplinary or other reasons.

The measures, which include screening inmates for potential suicidal tendencies and training guards how to intervene, appear to be making a difference.

Guards have reported preventing more than 60 suicides in segregation cells so far this year — out of more than 170 suicides attempted during the past five months in the state's 33 adult prisons.

"They've approached several guys who have nooses around their necks and they've intervened. They've saved them," said Correctional Capt. Gene Nies, who oversees the Folsom prison's segregation unit. "They know these guys. They start to recognize the signs. They know to check on them more frequently."

Even with the frequent checks, the guards can still be too late. On April 25, one of Nies' officers found 30-year-old Alberto Gomez hanging from a noose made of a bed sheet. Resuscitation efforts failed.

The numbers are down, though.

Last year, a record 43 inmates killed themselves in California prisons — nearly half in isolation units. California's rate of 25.5 deaths per 100,000 inmates is nearly double the nationwide prison suicide rate of 14 per 100,000, according to the federal Bureau of Justice Statistics.

Through Friday, 13 inmates had committed suicide, compared with 19 during the same period a year ago. Three were in the segregation units.

That reduction marks a rare hint of success for a prison system beset by multiple crises and one that has seen many of its operations placed under the authority of federal courts.

Three years ago, nearly 70 percent of California's inmate suicides were in segregation units, triggering intervention by a federal judge and the new prevention efforts.

"It is incredibly overcrowded, understaffed and locked down, with inadequate mental health care," said attorney Jane Kahn, who represents inmates in a class-action lawsuit.

Three federal judges are now considering limits on the prisons' population, which at 172,000 inmates is nearly double the designed capacity. Corrections Secretary James Tilton said the central effort to solve the problem is the state's new $7.8 billion prison and jail building program.

That program, coupled with transferring thousands of inmates to private prisons elsewhere, will free up space for treatment and rehabilitation programs, Tilton said.

While conditions are harsh throughout the prison system, efforts to prevent suicides are focused on the segregation units, which prisoners call "The Hole."

There, inmates are locked in their cells at least 23 hours a day for their own protection, disciplinary violations or investigations. Isolation terms average 68 days but can stretch for several months.

The sudden isolation, the stress from whatever incident prompted their transfer and the accompanying loss of possessions and privileges were found to be triggers for suicidal behavior, said Dr. Shama Chaiken, a chief psychologist with the corrections department.

John Garfield can relate to the sense of despair.

Now 62, Garfield was freed from the California Men's Colony in San Luis Obispo in April after serving nearly 30 years for conspiracy to commit murder.

He said he periodically became depressed as his parents and other relatives died while he served his sentence.

"That ate me up," he said. "I used to send out 80 or 90 Christmas cards. Now I'm down to 20. Each time something like that happens, it puts another spike in a guy."

He recalls friends who took their own lives, often after getting bad news or being cut off from family. One gave up after his wife divorced him, Garfield said.

"That was what broke the dam open," Garfield said from his home in Rialto. "He just said the hell with it. He had every drug you can think of. He did it on purpose, and off he went."

To save inmates from themselves, guards sometimes use pepper spray to incapacitate those who are trying to hang or cut themselves.

Some inmates thought to be suicidal are clothed only in quilted, smock-like garments that cannot easily be ripped and used as a noose. They are watched around the clock until their medications can be adjusted or mental health workers deem them no longer at risk.

The administration also agreed to spend $19 million this year and next to replace certain items in isolation cells, such as light fixtures and vent covers.

Michael Keating, the special master overseeing treatment of the system's estimated 30,000 mentally ill inmates, praised officials for expanding the 30-minute checks to the first three weeks after an inmate is placed in segregation, instead of just the first 72 hours, when the danger is highest. Some inmates are now allowed to have radios or televisions while in isolation.

While prison experts welcome the new procedures and additional spending, they also wonder what took California so long to get serious about addressing its inmate suicide problem.

California is far behind other states that have long been screening inmates for mental illness and suicidal intentions, said Lindsay M. Hayes, a suicide prevention expert with the National Center on Institutions and Alternatives. He predicted it could be five years before the department sees consistent results.

"We are hopeful, of course," said Terry Thornton, a spokeswoman for the California Department of Corrections and Rehabilitation. But she added, "We all feel it is way too soon to say whether all of these things are working."