REDLANDS, Calif. (KABC) -- The San Bernardino County coroner confirmed a Redlands couple's cause of death on Monday, nearly two weeks after their remains were found underneath their neighbor's home.

Stephanie and Daniel Menard died of "blunt force trauma to the head," according to the coroner. Their deaths have been ruled as homicides.

NOTE: The video above is from a previous report.

Earlier this month, Michael Royce Sparks, the couple's neighbor, was charged with two counts of murder and two special circumstance allegations in connection to the killings.

The 62-year-old was arrested days after the Menards were reported missing from their home in the Olive Dell Ranch nudist resort. The couple's remains were found in a concrete bunker underneath Spark's home.

According to Redlands Police Chief Rachel Tolber, a family member told officers that Sparks had admitted to killing two people prior to his arrest.

"It was while our teams were on site that the police dispatcher received information from an individual identified as a family member indicating that [Sparks] was involved in the disappearance and had admitted to killing two people and was threatening suicide," said Tolber.

The motive for the killings remains unclear, but neighbors said there was some tension between Sparks and the Menards.