Authorities are offering details into the brutal double slaying of an elderly couple nearly three months after they were allegedly killed by their next-door neighbor at a California nudist resort.
A frantic 911 phone call from a family member of 62-year-old Michael Sparks triggered a murder investigation after he allegedly confessed to the loved one that he killed two people and was about to kill himself.
He didn't mention the victims were his neighbors at the Olive Dell Ranch RV Park and Resort – Dan Menard, 79, and his wife, Stephanie, 73.
The couple – along with their beloved shih tzu, Cuddles – vanished four days earlier from their Redlands, California home. Their vehicle was found abandoned on the side of a road.
"We were out there following up, doing another canvas of the neighborhood," Redlands Police spokesperson Carl Baker told PEOPLE in an interview Thursday. "And while that team was out there on the site, that's when we received a call from a person who indicated that they were a family member of Michael Sparks and that he had told them, the family member, that he had killed two people and was going to commit suicide. He didn't say it was the Menards, but he said he had killed two people and was planning to commit suicide."
Police closed off the community and made several efforts to contact Sparks.
"They were making announcements over a loudspeaker," Baker explained. "We believed he had weapons and that he had barricaded himself. We had been told that he had built a basement."
The barricade situation dragged on for hours and police were forced to break out a window in Sparks' home to deploy a drone. But there was still no sign of him. Authorities made the decision to utilize an armored vehicle to smash through a wall.
"We used that to make entry to the house, pulled off the front wall," Baker told the outlet. "There was some consideration that he had booby-trapped it, but we determined that the [armored vehicle] would've set off any kind of booby traps."
Sparks was found hiding out in a self-made underground bunker that was "a little more than five feet deep, you could walk down there, but you might have to stoop," he explained. "It ran the length of the mobile home, the length and width of the mobile home."
He attempted to kill himself, but the weapon misfired.
A camera captured what appeared to be bags down in the bunker with Sparks, "and we determined that they were most likely human remains," Baker said.
Sparks surrendered and authorities confirmed the remains belonged to the Menards. Both died from blunt force trauma, a medical examiner ruled. Authorities believe Dan and Stephanie were killed either on their property or Sparks,' but they did not elaborate on a motive.
Their dog remains missing.
Friend Michelle Ann Archambault Reese said the couple didn't deserve the grisly fate they met.
"They had a great little home for the two of them and their dog," she said. "They were just somebody you wanted a hug from. They were just wonderful people."
Sparks has been charged with two counts of murder, jail records indicate.
It's unclear if he entered a plea.
He is due back in court January.
