The search warrant shows Hemet police recovered those items and a shovel, a .22-caliber spent shell casing and an empty gas canister on Nov. 18 at Jose Campos' home. Among the human remains was a charred human foot, the documents state.
Campos, Adrian Rios and Felicia Sharp, all 17, were reported missing earlier this month.
Investigators are trying to determine if the burned and fragmented remains belong to Campos or Rios. Sharp was initially reported missing, but was brought to the police station Wednesday by her parents.
Authorities have not released any information from her two-hour interview and said they have no suspects. Calls to the Hemet police were not returned Monday.
The warrant filed in Riverside County Superior Court outlines the investigation, which began Nov. 17 when Rios' mother, Elodia Lopez, called to report her son missing. She told police she had not seen him for two days and went to the Campos home, where her son was last seen by his friends.
Lopez found no one home but saw a bloody sneaker in the backyard and found drag marks in the dirt. She told police the sneaker looked like her son's shoe.
Police recovered what was later identified as a charred right human foot in the backyard and documented a fire pit with drag marks leading to it. They also noted a number of flies clustered on a saturated area of the ground, according to the warrant, which was first obtained by The Press-Enterprise newspaper. The human foot was found near a shovel.
Neighbors told the AP last week that they smelled a powerful and unidentifiable smell coming from the area of Campos' house the night of Nov. 15.
Matt Miller, who lives two houses behind the Campos address, said he spoke with two teenagers matching Campos and Rios' description after they ran onto his lawn in a panic that night.
The boys had red and swollen eyes and claimed they had been pepper-sprayed during a fight. They said the police were after them, Miller recalled, but they ran off before he could find out more.
Hemet is in a rural area about 90 miles southeast of Los Angeles.