The debate continues among state lawmakers over the use of controversial isolation units at four state prisons. A state Assembly committee discussed the units Monday.

The lawmakers heard from family members whose loved ones are being held in the Security Housing Unit, or SHU, at Pelican Bay State Prison in Crescent City.

"Long-term isolation is torture," testified Irene Huerta. Her husband Gabriel has been locked in the windowless unit since the prison opened in 1989.

Deputy corrections director Michael Stainer said the department was making some changes, but he defended the units as humane and necessary for prison security.

"We have these offenders within our SHU programs who are calling for assassinations at other prisons," said Stainer. "So yes, these are our most dangerous offenders."

A lawsuit by civil rights advocates contending security housing units like the one at Pelican Bay constitute cruel and unusual punishment is pending in federal court.

MORE: Meet an inmate in the SHU at Pelican Bay