(CNN) -- The California man who kidnapped 16-year-old Hannah Anderson "tortured and killed" her mother and brother before snatching her as she left cheerleading practice, according to formerly sealed warrants that were released Wednesday.
Investigators did not detail in the warrants how the torture was carried out, but they did reveal new details about how authorities believe James Lee DiMaggio carried out the killings and abduction.
"DiMaggio tortured and killed his best friend's wife and eight-year-old son. DiMaggio also shot and killed the family dog," according to one of the affidavits. "After the double homicide, DiMaggio set the house on fire."
The details were revealed the same day that a preliminary autopsy showed that DiMaggio was shot at least five times by an FBI tactical agent during a confrontation in the Idaho wilderness over the weekend. That confrontation ended a massive manhunt that began in San Diego County, California, after authorities found the bodies of Hannah's mother and brother in his burned out home.
DiMaggio sustained at least five gunshot wounds to his upper torso, arms and head, Valley County, Idaho, Coroner Nathan Hess said. An exact cause of death will not be formally released until toxicology tests have been completed in six to eight weeks, he said.
The first indication of a problem came the night of August 4, when firefighters and sheriff's deputies responded to a report of a fire at DiMaggio's log cabin.
As firefighters were trying to put out the blaze, they noticed flames in the home's detached garage, according to search warrant and arrest warrant affidavits dated August 6.
A couple of firefighters quickly doused that fire while others focused on putting out the fire engulfing the cabin.
Inside the garage, a fire captain discovered the body of Hannah's mother, 44-year-old Christina Anderson, face down in the garage, covered with a tarp. The documents revealed that a crowbar and what appeared to be blood were found next to Anderson's head.
Near the body, sheriff's deputies found the body of a dog covered by a sleeping bag, according to the affidavits. What appeared to be blood was found near the dog's head, the documents said.
As firefighters and investigators were making their way through the burned out remains of the house, they found the badly burned remains of a small child, the affidavits said.
Authorities issued a nationwide Amber Alert for Hannah and Ethan on August 5, but the documents revealed that authorities suspected the remains were those of the boy.
Warrants also were sought by the San Diego County sheriff's investigators to place "tap and trace devices" on DiMaggio's e-mail, Facebook and cell phone accounts as well as Hannah's phone, e-mail and social media accounts.
In the affidavits, authorities indicated that Hannah's cell phone was turned off on the afternoon of August 4, the same day and about the same time she was last seen as she was picked up from cheerleading practice at her high school. The affidavit does not identify who picked her up.
Shortly before her phone was turned off, there were 13 calls that day between Hannah and DiMaggio, according to the warrants.