Inside security housing units at Corcoran and Pelican Bay prisons

Lt. Anthony Baer (not pictured), a spokesman at Corcoran State Prison, said security housing units for solitary confinement help officers keep tabs on gang activity and tamp down violence. “These are inmates who have proven they cannot play well with others,” he said.

Inmates found guilty of specified offenses -- including murder, attempted murder, drug trafficking, arson, and extortion -- are confined in security housing at Corcoran State Prison.

Richard Heyer, 54, is a Corcoran State Prison inmate and lives in solitary confinement.

A display of shanks, handmade weapons made out of materials in prison, was shown to the media by prison guards who said they were confiscated from the inmates at Corcoran State Prison.

A deputy checks on inmates serving time in solitary confinement at Corcoran State Prison.

Brent Shelton, who is legally blind from a shotgun blast incident, is housed inside a security housing cage during yard time at Corcoran State Prison.

California State Prison in Corcoran.  (Barbara Davidson / Los Angeles Times)

Javier Zubiate, an inmate in solitary confinement at Pelican Bay State Prison, waits in a holding cell.

Closed-circuit cameras at Pelican Bay State Prison are protected by razor wire.

Inmate Javier Zubiate stands in the concrete recreation area in one of the solitary confinement units at Pelican Bay State Prison.

Inmate Javier Zubiate rests his feet in a solitary confinement unit at Pelican Bay State Prison.

Pelican Bay State Prison inmate Jeremy Beasley shows his tattoos and handcuffs. At Pelican Bay since 1998, Beasley went to prison on a life sentence for murder and has since tried to kill another inmate and assaulted a guard.

Pelican Bay State Prison inmate Javier Zubiate shows his tattoos and prison garb. Zubiate is a convicted killer serving time in solitary confinement.