AS his ailing mother clings to life, coldblooded killer SCOTT PETERSON remains haunted by his failure to tell her how he murdered his wife LACI and their unborn son, sources say.

“Scott is devastated over the fact that his mom Jackie is dying and he never came clean to her,” a family source told The ENQUIRER.

“He most likely won’t get to see her before she passes on, and when that happens, he may end up suicidal. For the many people who hate Scott for what he did, it serves him right.

“As Scott rots in jail, he’s going to suffer tremendous guilt that he never told his mother the truth.”

Ron Frey – father of Scott’s mis­tress Amber Frey, a key witness at his trial – told The ENQUIRER: “It’s time for Scott to finally con­fess exactly how and when he killed Laci.”

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

He pleaded NOT GUILTY to the murders and has never revealed what happened before he dumped Laci’s body in the icy waters of the San Francisco Bay.

Meanwhile, the fiend’s mom Jack­ie has battled respiratory problems for years and was on oxygen during his trial. Her husband, Scott’s father Lee, recently brought her home from the hospital so he could care for her.

“I don’t remember the last time Jackie was able to visit Scott. It’s been a long time,” Lee told The ENQUIRER.

“She’s been far too sick to go with me to the jail or even speak to Scott on the phone. She’s writing him letters when she can.”

An appeal of Peterson’s convic­tion is pending, but his father said: “It may take up to two years until we hear anything. Still, we’re hopeful. We believe Scott is innocent.”

The friend added: “This is all Scott’s fault. Scott’s arrest took such a toll on Jackie’s health – it’s no wonder she’s so sick. This whole situation is literally killing her.

“I know she’s hopeful the ap­peal will go through and she’ll live long enough to see her son set free, but that’s not likely to happen.”

Amber Frey, the beautiful blonde mas­sage therapist who carried on an affair with Scott, believing that he was single, bravely helped police after Laci vanished.

And her evidence against him was a prime factor in the jury’s verdict of guilty.

Her father told The ENQUIRER: “Jackie has always been Scott’s strongest sup­porter, and she may be the only person Scott ever truly loved. But she must know in her heart that he killed his wife and child.”