Morgan Geyser, who admitted to stabbing her classmate Payton Leutner 19 times in 2014 to impress the fictional character Slender Man, is missing after cutting off her electronic monitoring bracelet and leaving a group home in Madison.She was last seen near Kroncke Drive with an adult acquaintance and police have issued an alert with a security video image to find her.Earlier this year she was placed in the group home following her release from a mental health institute where she had been committed for nearly seven years.