Updated

A retired American couple was found fatally shot inside their Mexico home after a botched robbery Saturday, authorities said.

Jo Anne Butler, 69, and Ray Ball, 72, of Prescott, Ariz., were killed in their Bahia de los Angeles home, about 380 miles south of the U.S. border on the Gulf of California, the San Diego Union-Tribune reported.

“It was an attempted robbery, and an individual went to defend his property, and that’s when they shot him,” Octavio Lopez, a top local government official, told the Union-Tribune. “This is the first time we’ve had something like this happen.”

Neighbors told the newspaper they believe they were killed over a dispute involving a 22-foot-long fishing boat at the property. A neighbor, who asked not to be identified, said they heard gunfire at around midnight and saw an SUV pulling a boat toward the water. However, the thieves were unable to successfully move it.

Another neighbor, identified by the newspaper as former off-road racing champion Roger Mears, discovered the pair’s bodies. Authorities said Ball had 18 gunshot wounds and Butler had two in her legs.

“We have no memory of having a shooting here,” Tom Mitchell, an American who also has a home in Bahia de los Angeles, told the Union-Tribune. “This has taken it to a level that no one here has experienced.”

Authorities have not released details into what may have led to the shooting. Neighbors told the newspaper that Ball may have heard a noise outside and took his bat to investigate when he was shot as he opened the back door of his home.

“This was so out of character for our community,” Mitchell said. “These guys didn’t hesitate to kill. They basically murdered both of them.”

Authorities have not named any suspects in the couple’s killings. No arrests have been made.