Paul Flores, the convicted killer of college student Kristin Smart, was stabbed Wednesday at a California prison, the second time he has been attacked by a fellow inmate in the past year, officials said.Staff witnessed the stabbing shortly before 3:30 p.m. in the recreation yard at Pleasant Valley State Prison and were able to end the assault using verbal commands, according to a statement from the California Department of Corrections and Rehabilitation.An injured Flores, 47, was transported to an outside medical facility for treatment and later returned to the prison in fair condition, officials said.The inmate suspected in the assault, whose name was not released, was placed in restricted housing, the corrections department said. The attack is being investigated as an attempted homicide.Two suspected inmate-manufactured weapons were recovered, the department said. No other staff or incarcerated people were injured.Flores was slashed in the neck in August by another inmate in the yard of the same prison in Coalinga in central California. Flores was hospitalized and returned to the prison two days later.The man accused in that attack, Jason Budrow, has pleaded not guilty to felony charges including attempted murder and assault by an inmate serving a life sentence.Authorities didn't mention possible motives for either attack.Flores is serving a sentence of 25 years to life for the murder of Smart, a 19-year-old who disappeared from California Polytechnic State University in San Luis Obispo over Memorial Day weekend in 1996.Prosecutors maintained Flores killed Smart during an attempted rape in his dorm room at the university, where both were first-year students. He was the last person seen with Smart as he walked her home from an off-campus party. Her body was never found.Flores was arrested in 2021, convicted in 2022 and sentenced last year.