BAKERSFIELD, Calif. (KGET) — Prison was no picnic for Ronald Feldmeier.

Dubbed the “pillowcase rapist” for sexually assaulting multiple women in Sacramento, he was regularly targeted by other inmates during his 35 years behind bars. Assaults twice left him with a broken jaw and multiple rib fractures; on one occasion he was stabbed in the back.

Feldmeier estimated he was knocked unconscious 20 times.

“I was, I don’t want to say constantly, but, my best estimate, I was certainly assaulted every year I was in prison, and sometimes quit often,” Feldmeier said.

Following his release, he would never intentionally do anything that would send him back, the now-71-year-old testified Wednesday.

He said his diminished cognitive abilities and his belief that someone would tell him when he had to register led to his arrest in 2020 on a charge of failing to register as a sex offender.

“I wasn’t aware of the necessity and nobody told me to do it,” Feldmeier said.

When prosecutor Leanne Wilder displayed a parole document stating Feldmeier must register as a sex offender, he acknowledged it bore his signature and initials. But he said he doesn’t remember signing the form.

Wilder, during cross-examination, attempted to cast doubt on the severity of Feldmeier’s alleged cognitive impairment, eliciting testimony he took multiple courses at Cal State Bakersfield in 2019 and 2020 and received at least two As and some Bs.

If convicted, Feldmeier could be returned to prison for the rest of his life. Trial is expected to continue Thursday.

His attorney, Kyle J. Humphrey, has said Feldmeier became used to the routine in prison, where you’re told when to eat, sleep, shower, etc., and was adjusting to life on the outside when arrested. He said Feldmeier had been staying at a sober living home and wearing an ankle monitor as required by parole; he simply forgot to register.

Feldmeier became known as the “pillowcase rapist” for using the covering to stifle his victims’ screams during assaults committed in the 1980s.

In a separate case, Feldmeier faces a kidnapping charge after picking up a woman in June who told police she jumped from his vehicle after he repeatedly refused to stop and let her out. The woman suffered cuts and scrapes police said were consistent with jumping from a moving vehicle. Feldmeier denied keeping the woman against her will and said she’d been acting strangely, and was possibly under the influence.

A trial is scheduled to begin next month.