a tutorial: how shock collars work

Lisa Haenel was murdered on January 15, 1993. On that day, Lisa, an honor student at Old Mill High School, vanished while walking her usual path to school. She was reported missing by her mother and a search was initiated. The following day, her mother's boyfriend found Lisa's body ditched in a ravine behind the school. She was almost completely nude except for a sock, with stab wounds and strangulation marks on her body. Lisa was not sexually assaulted, so seminal fluid could not be collected.