The couple was last seen on August 24 at their home in the Olive Dell Ranch resort in San Bernardino County. Human remains were found underneath Sparks’ home after he was arrested last week, following a tense and lengthy standoff.
Police have said they believe the remains are those of the Menards, who lived next door.
“We know they’re dead, and we know there’s two victims,” Anderson said about the reasoning for the charges.
Sparks is set to appear in court Wednesday and is ineligible for bail, jail records show. CNN has been unable to identify an attorney for Sparks or locate family members.
• Redlands Police Chief Rachel Tolber said one of Sparks’ relatives led them to him. Hours prior to his arrest last week, a family member called police saying he was involved in the Menards’ disappearance.
He “had admitted to killing two people and was threatening suicide,” Tolber said about Sparks.
“I believe that there may have been other people that were texted, but the initial call that started our focus on him was from the family,” Tolber added.
Officials couldn’t discuss a potential motive for the killings and Anderson said it did not appear to be planned.