Folks in the Waukesha, Wisconsin area are up in arms over "Slenderman" Halloween costumes being sold there just months after a gruesome stabbing linked to the fictional horror-story character.

Two 12-year-old girls stand accused of stabbing their friend 19 times and leaving her to die in the woods.

Police believe the horrifying crime was motivated by the girls' desire to please the "Slenderman" character.

Morgan Geyser, 12, has been ruled not mentally fit to stand trial for the attempted murder and was committed for treatment. Anissa Weier, 12, is also set to be examined to determine whether she is fit to stand trial. Both were charged as adults in the case.

The victim, who has not been publicly identified, is reportedly recovering and has returned to school.

Given what happened in May, many residents feel the costumes should be pulled off the shelves. Party City did so, but Spirit Halloween reportedly had not.

It's still being sold online, however.

Watch the "Outnumbered" debate above.