A manhunt is underway to find the person German police say stabbed his nine year old neighbor to death and posted a video of the crime online. Police say 19-year-old Marcel Hesse made a video of himself killing the child, then holding up his bloody hands while boasting about what he did. They say the video was posted on the dark net, a hidden part of the internet often used for criminal activity. Another user reportedly alerted authorities to the video.