Convicted coldblooded killer Scott Peterson -- on death row in San Quentin, Calif. -- is mourning the death of his mother, Breaking Celebrity News has exclusively learned.

Jackie Peterson, who stood by her evil son during his trial, died earlier this month aged 70, multiple sources close to the family confirmed.

She had been battling cancer.

"Jackie's death has not been announced publicly," the insider said. "The family does not want the notoriety that will come with it."

Jackie had battled respiratory problems for years and was on oxygen during her son's notorious trial.

Her husband, Scott’s father Lee, recently brought her home from the hospital so he could care for her in her dying days, the source said.

Peterson, 40, has been on death row for seven years since being convicted of killing his pregnant 27-year-old wife and their unborn son Conner on Christmas Eve 2002.