Buyers will seek out anything connected with high-profile killers, including fingernail clippings, letters and artwork

The Murder Museum bragged about selling two rocks snatched from the scene of Florida’s worst school shooting.

“Sold! Two rocks taken from the grounds of Marjory Stoneman Douglas High School. $85 shipped,” read a post on its Facebook page, which also included a photo of the killer.

It isn’t the only dealer of morbid merchandise known as “murderabilia.” This macabre market appeals to true crime collectors seeking such things as Charles Manson’s dentures, Ted Bundy’s glasses and the Virginia Tech shooter’s calculator.

Andy Kahan, a Texas-based victims advocate, has tried unsuccessfully for years to outlaw the sale of murderabilia, and he said he fears that Parkland, Fla., will be the next tragedy that dealers use to turn pain into profit.

“I am of the opinion that you shouldn’t be able to rob, rape and murder and then turn around and make a buck off of it,” said Kahan, who worked for the city of Houston. “When you find someone is making money off your loved one’s death, it’s like being gutted all over again.”

Buyers will seek out anything connected with high-profile killers, including fingernail clippings, letters and artwork.

The Murder Museum offered a “certificate of authenticity” and claimed that a student had taken the rocks, and a photo showing the stones on school property. The location on campus was not specified.

“Stay tuned for the next auction in a few weeks,” the store wrote on Facebook, adding that it was going to sell a yearbook with the Parkland killer’s photo.

The Murder Museum deleted its post about the rocks when contacted by the South Florida Sun Sentinel and did not respond to a request for comment.

Facebook removed two online shopping tabs of gruesome goods being sold by the Murder Museum and Supernaughts True Crime Gallery in response to the newspaper’s questions. A Facebook spokeswoman said the merchandise violated the social network’s commerce policies, which prohibit the sale of offensive offers or products.

Broward County Public Defender Howard Finkelstein said he’s aware that Parkland school shooter Nikolas Cruz could be a source of murderabilia, and his office has taken steps to prevent that from happening.

“Zero fan mail has gotten through” to the killer, he said. “If someone sends a message to save his soul, then we would treat that differently. God is different.”

Finkelstein called the sale of such merchandise “blood money” and “sick and perverted.”

“We will not facilitate or allow him to write a book, sell a movie or bodily fluids,” he said. “That would be wrong, and we will not be a part of it. Our job is to save his life, not to add to his commissary.”

Nearly 200 people have tried to see Cruz, Finkelstein said.

It’s unclear whether taking rocks from the school would be considered theft. A Broward Sheriff’s Office spokeswoman did not respond to a request for comment. Earlier this year, a couple was charged with pilfering a memorial to victims at Stoneman Douglas, taking teddy bears, plaques, pinwheels and other tokens of remembrance.

Florida-based Supernaughts devotes an entire section to school shooters on its website. The store priced the Virginia Tech shooter’s graphing calculator at $4,500.

The late serial killer Charles Manson’s dentures were listed for $50,000, while Ted Bundy’s glasses are offered at $75,000.

Eric Holler, owner of Jacksonville-based Serial Killers Ink, defended the industry, saying he’s just one of many who profit off crime.

“I have the First Amendment on my side,” Holler said. “I run a legal business. I am breaking no laws. This is a capitalist country. I am free to make a buck as I see fit as long as it is legal.”

Holler said he would sell a letter written by the Parkland shooter, but he would not solicit any.

“Somebody could use those to dissect his mind,” Holler said. “Items from the school or tied to the victims — hell no, I wouldn’t sell those.”

But Finkelstein said that won’t happen anytime soon because incoming and outgoing mail is being controlled by the public defender’s office.

Holler said his customers are interested in the criminal mind. Top-selling items are artwork and letters from serial killers.

A painting by serial killer John Wayne Gacy could be a “conversation piece,” Holler said. Some of Gacy’s most valuable paintings are self-portraits of himself dressed as Pogo the clown, listed as high as $50,000.

Holler said he’s also helped victims of mass shootings, assisting Aurora, Colo., movie theater shooting survivor Carli Richards in selling bullet fragments that were taken from her body. He said he donated the proceeds to Richards.

U.S. Sen. John Cornyn, R-Texas, has tried several times to get bills passed outlawing the practice.

But such a law would likely be fraught with constitutional issues, said Ken Paulson, president of the First Amendment Center. “There would be a tremendous burden on the state to establish this kind of law doesn’t amount to an unconstitutional taking of property,” he said.

The courts have ruled that a prisoner’s First Amendment rights — such as being able to send and receive mail — must be balanced against the prison’s need to maintain safety and security. The Broward County Sheriff’s Office has returned letters addressed to the Parkland shooter, citing security concerns.

Other retailers have shunned murderabilia. The website eBay banned the sale of such merchandise in 2001. Florida passed a “Son of Sam” law to prevent prisoners from profiting from their crimes through book and movie deals. The term is derived from New York serial killer David Berkowitz.

Florida’s law stipulates that prisoners receive no compensation, with proceeds instead going to their dependents, victims, the courts and Crimes Compensation Trust Fund.

However, items associated with high-profile Florida cases have found buyers. George Zimmerman sold for $250,000 the gun that he used to kill the unarmed teenager Trayvon Martin. In 2013, Zimmerman was found not guilty of second-degree murder and manslaughter.

The appeal of murderabilia could be rooted in the collector’s desire to channel darker urges into “something more socially appropriate,” said Kit Yarrow, a professor of psychology at Golden Gate University. Also, society has become increasingly obsessed with fame — even those who become infamous through murder, she said.

Holler said he knows he’s often viewed as a villain for selling murderabilia, but his business couldn’t succeed without demand for his items.

“Crime sells,” he said. “People buy crime.”