A fellow inmate told the Modesto Bee that Peterson's correspondents include a woman serving time for murdering her husband. A guard read the letter aloud, inmate Chris Young said.
Peterson has pleaded not guilty to double-murder charges that make him eligible for the death penalty if convicted.
Late last week, a judge issued a gag order barring lawyers, witnesses and police officers from publicly discussing details of the case. Judge Al Girolami said the gag order was the only way to stop leaks and rumors from derailing Scott Peterson's right to a fair trial.
Stanislaus County sheriff's Deputy Tom Letras confirmed that Peterson gets more mail than most inmates, but would not elaborate.
It's not uncommon for young men accused of terrible crimes to receive letters from female admirers, said Jeanette Sereno, a criminal justice professor at California State University, Stanislaus.
"If you don't see him as responsible for the (slayings), he's a very sympathetic young man, someone the whole world is against," Sereno said. "People out there have a need to come to the rescue of someone beleaguered."
Young, 29, also told the newspaper that extra security precautions have been taken at the Stanislaus County jail to ensure Peterson's safety. For instance, inmates on meal duty have been told to select Peterson's trays randomly to avoid poisoning, he said.
Peterson was arrested after his wife's body and the remains of their unborn son washed ashore in San Francisco Bay. He has denied any involvement in his wife's disappearance and death says he was out fishing on the bay the day his wife disappeared. His attorneys have suggested a satanic cult may have abducted and killed his wife.