Updated

Seven decades after the discovery of a little boy's mutilated body sparked panic that a sexual predator had struck again, detectives say they've cracked the case and the fear was unwarranted.

The boy, 7-year-old Dalbert Aposhian, wasn't killed — he drowned while fishing in San Diego Bay, the sheriff's cold case squad announced Thursday.

The missing body parts noted in the autopsy as evidence of "multiple mutilating operations" were caused by sea creatures, officials determined.

Dalbert, a minister's son, had been missing for six days when four Navy sailors spotted his body in July 1933. The boy's eyes, fingers, lips and genitals were missing, sending the city into hysterics.

The San Diego Union splashed the news on its front page that a "maniacal killer" had taken his sixth victim. The first murder, the 1931 slaying of a 13-year-old girl, is the oldest open case in the sheriff's homicide files.

A local women's group demanded the city "be cleaned out of its underworld gangsters, prostitutes, immoral dance halls, burlesque theatres, burglars and degenerates." A mentally unbalanced 19-year-old confessed to the crime in what turned out to be a confused attempt to impress his girlfriend.

Investigators at the time thought there was another explanation. Jack Confer, a 10-year-old friend, told deputies the two were fishing off a pier when Dalbert lost his balance and fell in. Jack panicked and ran.

The deputies believed the boy's story, but Dr. Frank Toomey, who conducted the autopsy, wasn't swayed. He remained convinced that Dalbert had been sodomized, mutilated by the type of a knife issued to Navy men and had bled to death before he was thrown in the water.

Toomey claimed to have found semen on the boy's body. There was no water in the lungs, he noted, and "all missing parts had been totally cut away."

Another autopsy conducted two years later concluded the boy drowned, but the case remained open.

Seventy-two years later, Detective Curt Goldberg took a crack at it. He consulted Dr. Jon Lucas, a forensic pathologist at the San Diego Medical Examiner's office, who determined Toomey had gotten swept up in the hysteria of the day.

"It was classic crustacean/fish activity," Lucas said. He noted that not all drowning victims have water in their lungs and sperm can't survive in open water for six days. His ruling of accidental death effectively closed the case.

For Van Aposhian, now 73, the ruling on his big brother's death was bittersweet. Although he always suspected Dalbert drowned, he was relieved to know for certain. His mother, however, went to her grave believing Dalbert's death was anything but accidental.

"My mother had always held to the fact that he had been kidnapped and murdered," he said. "They knew that all of that would be resolved once they were in heaven, so they're in heaven now."