It's been three years since 15-year-olds Anissa Weier and Morgan Geyser lured their classmate to a park in Milwaukee and stabbed the victim 19 times in the name of fictional internet lore.
Now, the unique case is coming to a close, with the jury expected to come to a verdict this weekend.
The story captured global attention in 2014, when the suspects' motive was revealed - to placate the fictional supernatural character 'Slender Man'.
Originating on internet horror forum Creepypasta, Slender Man stories often revolved around matters of stalking, abduction and traumatisation.
The figure inspired video series Marble Hornets and first-person survival game Slender.
Weier is currently fighting to stay out of prison. Despite reaching a plea agreement in August and admitting to playing a role in the near-fatal stabbings, she has pleaded not guilty by reason of mental illness.
Professor of psychology at UW-Madison Dr Gregory Van Rybroek testified she was delusional, believing Slender Man was real.
"In her mind she was acting out of a sense of altruism, that she was saving someone," he said.
Prosecutors said another motive was to save her friendship with Geyser.
The defence concluded presenting its case on Thursday.