Autopsy: Gunshots killed all 9 in Fresno house
Suspect cooperating with investigation, police chief says
The sons of Marcus Wesson defend him.
Wesson faces nine counts of murder.
Gallery: Bodies found in Fresno home
Family depicted as nomadic, insular
Map: Fresno, California
FRESNO, California (CNN) -- Autopsies performed on all nine bodies found stacked in a home in Fresno indicate the victims were shot to death, the Fresno County coroner said Monday.
Marcus Wesson, 57, was charged with nine counts of murder Friday after the discovery of the bodies -- including those of at least two children whom police said Wesson fathered with one or two of his daughters.
Bail was set at $9 million. He is expected to be arraigned Wednesday at 1:30 p.m. (4:30 p.m. ET).
Coroner Loralee Cervantes said all of the victims were shot Friday. She said there was a pattern to their deaths but would not elaborate. Toxicology tests will be performed on the victims to determine if they were drugged.
"I can just say that there are some variations in a pattern. And obviously a pattern exists because there are multiple victims," Cervantes said.
Fresno police Chief Jerry Dyer said police were not discounting the possibility that more people were involved in the crime.
"We do not want to be too narrowly focused on our investigation to exclude anyone, but we do believe absolutely that he is responsible for the murder of all nine victims," Dyer told CNN.
Dyer said at an afternoon news conference that Wesson was being cooperative and providing information and that he has been calm and articulate.
He said investigators were also looking at whether the killings might have been ritualistic and whether a religious cult might have been involved.
"We are not certain what transpired in the house," Dyer said, adding that the time of the deaths would not be released by the coroner's office because it was an important part of the investigation.
Dyer said a search warrant served on the family's home Sunday and on another location in Fresno resulted in the seizure of several items "that may assist us with the motives involved in this case."
Dyer said earlier that Wesson appeared to have had sexual relationships with four women.
"In terms of his lifestyle and the dress of the women; we've heard from the neighbors that they were isolated, he was a controlling person, very controlling of the children, controlling of the women," Dyer said.
"Their dress was unique, very conservative, and so we're looking at all of the aspects as to the lifestyle, which may give us a feel as to what the motive was.
"It is our belief that Wesson fathered most if not all of the children in the house," Dyer added at the afternoon news conference.
He said police were told "that the children did not leave the house very often."
Charlie Clark, a real estate agent who was trying to sell Wesson's home, said his client was always "considerate, timely, articulate [and] very courteous," but he did sense "some controlling nature."
Clark, who knew the family for about 18 months, told CNN the family came into his office several times.
"It was clear that two of the ladies were his daughters, there's no question about that. The third lady, who was always very cordial, I was still not certain what her relationship was with Marcus," Clark said.
Clark also said he visited the home several times, and the children were always there.
"I could never figure out who belonged to who," Clark said.
Police found the bodies Friday after they were called to the home by two women who said they were trying to get custody of children they had turned over to Wesson. Wesson was inside the house.
After he came out, covered in blood, police entered the home, where they found the bodies of a 24-year-old woman; five girls, ages 17, 8, 7, and two 1-year-olds; and three boys, ages 7, 4 and 1.
The bodies were piled atop one another and clothing was intertwined among them, authorities said. Twelve empty coffins were found in a front room, authorities said.
Dyer said police had been called to Wesson's house six times in the past three years for various reasons, but he said none of the calls related to the welfare of the children.
He said the coroner's office is having trouble identifying all the bodies, and asked anyone with information about who was in the house to call a message center set up by police.
On Saturday, the suspect's 19-year-old son, Serafino Wesson, said his father was "the best dad anybody could ever have." (Full story)
CNN's Stan Wilson contributed to this report.