The husband and wife approached the La Paz County Sheriff's Office and revealed how the skeletons in their closet ended up at the bottom of the river in Parker.
"They were nervous at first," Lt. Curt Bagby said. "They thought they might be in trouble. But when they finally came in, they brought a photo as proof that they were the ones who put them there."
>>VIDEO: La Paz County Sheriff's Office & Buckskin Fire Dept. find underwater skeleton tea party
The pair, who may identify themselves publicly next week, came forward after seeing all the media attention surrounding the skeletons. The Sheriff's Office has no plans to file any charges since the skeletons weren't endangering anyone, Bagby said.
"We try not to encourage people to do this kind of thing, but it was relatively harmless," he said. "It was deep water, they were wedged between some rocks, and there was no reason to expect someone would find them."
A man snorkeling in the river near the Arizona and California border spotted the skeletons about 40 feet underwater Monday. Believing they were actual remains, he contacted authorities. But it soon became clear to a Buckskin Fire Department diver that they were fake.
The skeletons were wearing sunglasses with one holding a sign that includes the words "Bernie" and "dream in the river," although the entire sign was not legible. The sign also had the date of Aug. 16, 2014.
Bagby said he thought at the time "Bernie" was likely a reference to the movie "Weekend at Bernie's." In the 1989 film, the two main characters lug around their dead boss for days, losing and recovering his body several times. At one point in the film, Bernie's corpse falls off a boat and into water.
The couple told deputies how they and another diver placed the skeletons on lawn chairs last year, tying them to underwater rocks. The group thought it would make for a humorous landmark. According to Bagby, all three have returned to the site several times to clean the skeleton, the Today's News-Herald said. It was in March that they added the second skeleton, "Bernadette."
Unless federal agencies have any issues, the skeletons will remain in place, Bagby said.
"We're thinking of leaving them in the waterway - something like a geocache, where we can let divers try to find them. I can't see this being a liability or risk to lake-goers," he said.
Copyright 2015 The Associated Press modified.