Former cult leader Charles Manson, who was hospitalized earlier this week, was too weak to undergo surgery, reports said Friday. The 82-year-old, who inspired his followers to kill seven people in 1969, is serving nine concurrent life sentences for the murders and has been denied parole 12 times.

Manson was admitted at a medical center in Bakersfield, California, for gastrointestinal bleeding Sunday. Doctors wanted to perform the surgery shortly after Manson was admitted but he refused to undergo the procedure. TMZ reported the former cult leader later agreed to go under the knife and was scheduled for surgery Thursday but was found too weak for the procedure.

The 82-year-old mass murderer was back behind bars, the Los Angeles Times reported Friday.

“Inmate Manson is at California State Prison-Corcoran,” California Department of Corrections and Rehabilitation spokeswoman Terry Thornton reportedly said.

Manson, who has been in jail since 1971, was convicted of first degree murder and conspiracy, along with three of his followers: Charles “Tex” Watson, Patricia Krenwinkle and Susan Atkins.

The group was convicted of killing the actress Sharon Tate, who was pregnant at the time, her hair stylist Jay Sebring, student Steven Parent, coffee heiress Abigail Folger, writer Wojciech Frykowski, supermarket owner Leno LaBianca and wife Rosemary LaBianca over a span of two days in 1969. Leslie Van Houten was convicted of murdering the LaBiancas.

The 82-year-old has had over 100 violations during his four decades of imprisonment, People Magazine reported Friday. He was also found in possession of three contraband cell phones, had refused to submit a urine sample for a drug test and threatened prison staff.

“He threw hot coffee on a guard and spit on a guard’s face,” retired Los Angeles County prosecutor Stephen Kay told the magazine. “He was a nasty prisoner.” Kay added that Manson “never had any respect for women.”