One time a homestuck fan tried to shoot a fursuiter in the head who was performing on a stage, I don't know when, but it grazed the guy's head instead of killing him.
The fursuit head was exploded on one side and covered in blood; the missed bullet still sliced his head.
Not exactly a fursuit murderer, but still related to furries.
Speaking of homestuck fans, this one isn't attempted murder, but some different homestuck fan threw a steel bucket at another homestuck fan's head because of the lore or something, and it cut their head open leaving them bleeding on the ground.