Paul Flores, the 47-year-old man convicted of killing college student Kristin Smart who vanished in 1996, was attacked at a California prison for the second time on Wednesday.

Staff at Pleasant Valley State Prison witnessed another inmate stab Flores at around 3:30 p.m. on Wednesday in the recreation yard, the California Department of Corrections and Rehabilitation (CDCR) told The Associated Press.

The attack, which is being investigated as an attempted homicide, ended following verbal commands from staff, according to the CDCR, and two "suspected inmate-manufactured weapons" were recovered after the incident.

Flores was taken to a medical facility outside the jail to be treated for injuries and returned to the prison in fair condition. No other inmates were injured.

KRISTIN SMART KILLER PAUL FLORES SENTENCED TO 25 YEARS TO LIFE FOR CALIFORNIA MURDER

Kristin Smart killer Paul Flores

Paul Flores was convicted in October 2022 of killing Kristin Smart, a 19-year-old California college student who vanished in 1996. She was declared legally dead in 2002.

The corrections department said the unidentified inmate believed to be responsible for the attack has been placed in restricted housing.

This week's attack on Flores marks the second time he has been stabbed in the central California prison since he was sentenced to 25 years to life in March 2023.

CA prison

Paul Flores was stabbed in the yard at Pleasant Valley State Prison in California during an attack by another inmate. (AP Photo/Eric Risberg, File)

Flores was hospitalized for two days last August after inmate Jason Budrow allegedly slashed him in the neck during an attack in the prison yard. Budrow pleaded not guilty to felony charges, including attempted murder and assault by an inmate serving a life sentence.

Authorities have not released a potential motive for either attack on Flores.

CALIFORNIA INMATE CHARGED WITH ATTEMPTED MURDER IN ATTACK ON KRISTIN SMART'S KILLER

Paul Flores arrest photo

Paul Flores was arrested in the San Pedro area of Los Angeles on April 13, 2021 for the murder of Kristin Smart. (San Luis Obispo County Sheriff's Office via AP)

Flores was arrested in 2021 for the murder of Smart, a 19-year-old student at California Polytechnic State University who was last seen over Memorial Day weekend 28 years ago. He was convicted of the crime in 2022.

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Smart was declared dead in 2002 and her body has never been found.

The Associated Press contributed to this report.