The charges against Marcus Wesson were outlined by prosecutors in a document filed with the court Tuesday and were to be formally read at his arraignment Wednesday.
Wesson, 57, is accused of shooting a 25-year-old woman and eight children Friday before he surrendered. Authorities said he was being held on $9 million bail.
Police have not disclosed a motive, saying they are not sure if it was a dispute over custody of the children or was some form of ritualistic killing.
Authorities will use DNA to identify the victims, since it appears there were six different mothers, reports CBS News Correspondent Manuel Gallegus, and for two of the children, it appears Wesson was both their father and grandfather.
According to the coroner, it appears that none of the victims struggled or tried to escape. Authorities are looking into whether they were drugged before they were killed.
Authorities said Wesson appeared to wield absolute authority over his household and his large clan. The women would walk dutifully behind him in dark robes, did not speak in his presence and apparently worked to support him. The children were home-schooled because he did not trust public education.
Two of Wesson's sons said he was a good father and that the family had been raised as Seventh-day Adventists.
Neighbors and acquaintances had their suspicions about the man with the burgeoning family.
Over the years he led his nomadic clan of women and offspring from a squatter's camp in the mountains to a dilapidated sailboat, and finally to inland California, where he hauled them around in an old school bus.
He was convicted in 1990 of welfare fraud, he had failed to list the boat as an asset, and neighbors often wondered how he fed his family because he never seemed to have a job.
Diana Wohnoutka, who lived downhill from Wesson and his children in the early 1980s, said Wesson often spoke about God and his belief that he did not need to work for a living.
"He was definitely strange," Wohnoutka said. "He believed he didn't have to work. God would take care of him. That's how he always preached to us."
At one point, the children were made to sleep on doors that were set on top of sawhorses, she said. Wohnoutka also said Wesson often stopped to chat with her in-laws, leaving his young wife and at least a half dozen children waiting obediently in the hot sun in their small car.
Wesson raised eyebrows when he bought a dozen mahogany caskets from an antiques store in Fresno, saying he planned to use the wood to repair a boat, said store owner Lois Dugovic.
Wesson left the hand-carved caskets at the shop for nearly a year until the owners asked him to remove them. When he came to collect the boxes, his girls dutifully carried them onto his yellow school bus.
"Those girls loaded every one of them in there," Dugovic said. "It was the weirdest thing."
On Monday, three days after authorities removed the bodies from the house, police carried away the caskets as evidence.