This is a good example of how tricky it is to pin down just when a "code word", epithet; or indeed ANY quotation first came into use. Even with huge full text databases such as Google Books or commercial full text such as Ebsco databases, JSTOR, and Project Muse; or Factiva, Lexis Nexis Academic, Proquest, and other newspaper full text databases, we are generally depending on fairly unreliable Optical Character Recognition (OCR) searches. We very likely will miss many words that simply don't get picked up by the search software. If you are near a large academic library where you can try them out, you will notice striking differences in search results for EQUIVALENT searches of the same newspaper (same date range) in Factiva, Lexis, or Proquest, for example.
Factiva (a larger newspaper database than Lexis Academic, a journalism librarian colleague informs me) gets 38 hits in "all dates" for the search: "no human involved". The oldest one related to criminology is no. 37; "PROSECUTOR BLASTS MENENDEZES AS 'VICIOUS BRATS'. Linda Deutsch Associated Press. 669 words 12 December 1993 Los Angeles Daily News. This has a quote from Deputy District Attorney Pamela Bozanich: "While admitting that the Menendez family was "not an Ozzie and Harriet family where everyone was happy," she said the parents gave them the privileges of wealth. "The parents were willing to support them while they were spoiled, vicious brats," she said. She accused defense attorneys of using a tactic called NHI, a homicide detectives' sarcastic shorthand for worthless victims meaning "No human involved." "It is a sick kind of joke and that's what the defense is in this case. What the defense is saying is that Jose and Mary Louise Menendez were such horrible people, it's OK. Who cares if they are dead? The world is probably a better place without them."