Premier Episode of The Kill File is covering the Smiley Face Killer cases.

Sources:

https://www.wattpad.com/533380537-scary-stories-and-true-crime-17-serial-killers-who

https://allthatsinteresting.com/smiley-face-killer

https://www.exploreforensics.co.uk/ligature-marks.html

https://www.spiritualtravels.info/spiritual-sites-around-the-world/north-america/sinsinawa/

https://positivelypittsburgh.com/smiley-face-killer-fact-or-fiction/

https://homicidecenter.org/wp-content/uploads/2021/12/Research-Brief-on-Smiley-Face-Murder-Theory-FINAL.pdf

https://www.rollingstone.com/culture/culture-features/smiley-face-killers-conspiracy-tiktok-theory-1234738835/

Smiley Face Killers: A hunt for justice

https://www.gdinvestigations.com/patrick-mcniell