From the June 5 NYT Week in Review section, a piece by Thomas Vinciguerra on “The ‘Murderabilia’ Market”, beginning with an online auction of property belonging to Unabomber Ted Kaczynski:
The items put to auction were the latest high-profile examples of “murderabilia” — artifacts of notorious killers that end up in private hands. In the case of the Unabomber, the auction’s proceeds will go to his victims and their families.
But that is not typical. Almost always, the sellers are in the business for their own profit. And that makes for some strong feelings.
“It’s a sick and despicable industry,” said Andy Kahan, director of the Crime Victims Office for the City of Houston and the individual who coined the word murderabilia to describe it.
There’s a Wikipedia entry on murderabilia (“collectibles related to murders, murderers or other violent crimes”), also crediting Kahan as the portmanteauist responsible for the word.