Michael Sparks, 62, was arrested for murder late Thursday, days after the couple were reported missing, according to the Redlands Police Department. Police had been trying to locate Sparks on Thursday, breaching a home and conducting a search using remote video equipment to find him.
Sparks was not found at the home, but he was the same person who was being sought in the search, police said.
He has been booked murder at West Valley Detention Center.
Stephanie Menard, 73, and Daniel Menard, 79, were reported missing on Sunday, according to police. During a press briefing on Thursday, the Redlands Police Department said foul play was suspected after being tipped off by a source in the couple's neighborhood.
The location of the couple and their dog remains unknown, police said.
The couple was last seen at their residence on Olive Dell Ranch -- a family nudist resort -- at around 10 a.m. local time on Saturday. Their unlocked vehicle was found down the road from the residence that day, according to police.
Stephanie Menard's purse was found inside their residence along with both of their cellphones, according to police.
The couple's dog, a white Shih Tzu named Cuddles, was also missing.