Oxygen’s thrilling true crime TV event begins TONIGHT! Some killers are collectors who obtain perverse gratification by habitually stealing mementos from murder scenes, from jewelry to shoes, keys to even body parts. Others leave their mark at the crime scene, signatures of their personality that create insights into their profile. Oxygen’s 12 Dark Days of Serial Killers kicks off with the season premiere of “Mark of a Killer” tonight at 9/8c, only on Oxygen, the true network for crime.

For all the details on Oxygen’s 12 Dark Days of Serial Killers, visit: https://www.oxygen.com/crime-news/best-serial-killer-documentaries-how-to-watch-oxygen?sky=dis_SKS_CrimeOnline_270726250.