An Indiana man is accused of stealing the brains of dead mental patients from a museum and then selling them on eBay.

Indianapolis police report a person in San Diego, Calif., who is not implicated in the crime, bought the brains and, after inspecting the items, suspected they had been acquired illegally by the eBay .

Specifically, the eBay customer observed labels for the Indiana Medical History Museum affixed to the six jars that contained the human brains, which he had bought for a little over $600.

So, police said, the customer alerted the museum as well as the Indianapolis police department.

Police investigators then staged a sting operation to catch the brain seller -- and suspected thief -- in the parking lot of an area Dairy Queen ice cream parlor Dec. 16.

Police arranged for an eBay middle man to schedule a meeting for another organ-swapping deal with the brain seller, said a report by the Indianapolis Star newspaper.

David Charles, 21, of Indianapolis, who allegedly stole 60 jars of human tissue a day before, was arrested and charged with theft, marijuana possession and paraphernalia possession, according to court documents.

"They caught him in the act," Indianapolis Police Officer Christopher Wilburn told The Daily News. "We understand that organ and tissue procurement help medical advancements that assist millions of Americans."

But at this point, added Wilburn, "we just can't quite understand" why Charles stole the brains in the first place.

The Indiana Medical History Museum is located on the site of a former hospital that housed psychiatric patients from 1848 to 1994, media reports say.

In an interview with the Indianapolis Star, the museum's executive director, Mary Ellen Hennessey Nottage, said she was dismayed anyone would steal artifacts from the museum.

The brain tissue in question was procured from an estimated 2,000 patients whose remains were autopsied by the hospital from about the 1890s through the 1940s.

"It's horrid anytime a museum collection is robbed," Nottage said. "A museum's mission is to hold these materials as cultural and scientific objects in the public interest. To have that disturbed -- to have that broken -- is extraordinarily disturbing to those of us in the museum field."

Nottage, who indicted she's extremely grateful that a good portion of the stolen material has been returned to the museum, said she spoke to the erBay buyer who decided to report the transaction after he paid paid $670 for the brains.

"He just said he liked to collect odd things," she said.