The state prison system’s official title, “Department of Corrections,” was for decades nothing more than a euphemism, as was the official nomenclature for the system’s guards of “correctional officer.”

The system expanded from about 20,000 inmates during Jerry Brown’s first stint as governor to more than 160,000 when he began his second governorship. And even though new prisons had sprouted up all over the state, they were overwhelmed by the sheer numbers of felons, leading to federal court orders to reduce overcrowding.

The system was focused on warehousing – such as filling prison gymnasiums with triple-tier bunks – and punishment, with only token efforts at “correction” via basic education, addiction treatment, job training and psychological counseling. Not surprisingly, very high percentages of inmates released from the system committed new crimes and returned.

Fifteen years ago, the Department of Corrections became the Department of Corrections and Rehabilitation, supposedly signaling a new emphasis on reducing its revolving door culture.

Nothing much happened, however, until Brown returned to the governorship in 2011. He, along with a more liberal Legislature and penal reform groups pushed to reduce sentences, make parole easier, divert more felons into local jails and probation, and ramp up rehabilitation programs inside prisons – thereby, it was said, reducing prison overcrowding and “recidivism” by those returning to the streets.

The prison population has declined sharply, down at least 50,000 inmates from its peak, but a new report from State Auditor Elaine Howle indicates that the department isn’t living up to its “corrections and rehabilitation” title.

“Our analysis of inmates released from prison in fiscal year 2015–16 did not find an overall relationship between inmates completing CBT (cognitive behavioral therapy) rehabilitation programs and their recidivism rates,” Howle told the Legislature, which ordered her study. “In fact, inmates who completed their recommended CBT rehabilitation programs recidivated at about the same rate as inmates who were not assigned to those rehabilitation programs.”

Why? She suggests that the corrections department adopted rehab programs without fully delving into what works and what doesn’t, saying that the department “has not revalidated the accuracy of the tools it uses to assess inmates’ rehabilitative needs since recent statutory changes caused a major shift in the state’s prison population. Another potential reason is that Corrections has not ensured that vendors provide consistent and effective CBT programs that have been proven through research to reduce recidivism.”

The audit continues in that critical vein on a number of points, to wit:

—“Corrections has neither consistently placed inmates on waiting lists for needed rehabilitation programs nor prioritized those with the highest need correctly.”

—“Corrections has neither developed any performance measures for its rehabilitation programs, such as a target reduction in recidivism, nor has it assessed program cost‑effectiveness.”

—“High staff vacancy rates and a failure to place inmates on program waiting lists has resulted in Corrections not utilizing all of its programs’ budgeted capacity. Although Corrections has expanded its rehabilitation programs to all 36 prisons, prison staff have not enrolled the maximum number of inmates in each rehabilitation class.”

No one doubts the inherent difficulty of turning around prison inmates – especially since those remaining behind bars after population reduction tend to be hardcore, often violent criminals.