Geyser and Weier, who was released in 2021, previously told investigators that they feared the online meme figure Slender Man would harm their family members if they didn’t attack Leutner.

Slender Man is typically depicted as a spidery figure in a black suit with a featureless white face and regarded alternately as a sinister force and an avenging angel.

The story inspired increased media attention to the Slender Man character, as well as to the control the figure had on impressionable children. The character, which first surfaced online as a ...