A 12-year-old boy was arrested for allegedly killing his twin sister and injuring his mother in a knife attack at their Connecticut home. The victims were taken to hospital but the girl, Brigid Curtin, died. Her mother is listed in stable condition. The boy was arraigned in his hospital bed at Connecticut Children's Medical Center on one count of murder with special circumstances and first-degree assault. InsideEdition.com's Keleigh Nealon (http://twitter.com/KeleighNealon) has more.