Episode 1: The Murder of Claudia Maupin & Oliver "Chip" Northup

Claudia and Chip (image found here)

Chip (far left) and the rest of The Putah Creek Crawdads (image found here)

Daniel Marsh's mug shot at the time of arrest (image found here)

Sources:

https://www.leagle.com/decision/incaco20180222030

https://www.vexplode.com/en/tedx/embracing-our-humanity-daniel-marsh-tedxdonovancorrectional/

https://www.google.com/amp/s/www.davisenterprise.com/local-news/police-teen-confessed-to-killing-davis-couple/%3famp=1

https://www.cbs.com/shows/48_hours/video/8k7fcYQfl2g1tA8A_AFzsP_Hknnzj1U5/fbi-agent-analyzes-15-year-old-killer-s-confession/

https://www.google.com/amp/s/www.thereporter.com/2013/09/14/disturbing-details-in-davis-slaying/amp/

https://sacramento.cbslocal.com/2014/09/03/paramedic-elderly-davis-couples-organs-were-removed-after-stabbing/

https://www.google.com/amp/s/www.abc10.com/amp/article/news/local/davis/daughter-of-davis-murder-victim-proud-her-mother-fought-back/103-277603414

https://www.google.com/amp/s/www.davisenterprise.com/local-news/crime-fire-courts/marshs-mother-gives-early-testimony-in-homicide-case/%3famp=1

https://patch.com/california/davis/chip-northup-claudia-maupin-killed-community-groups-respond

https://www.google.com/amp/s/www.davisenterprise.com/local-news/crime-fire-courts/family-community-mourn-couple-slain-in-south-davis-home/%3famp=1

https://en.wikipedia.org/wiki/Psychopathy_Checklist

https://ssristories.org/psychologist-casts-doubt-on-marsh-insanity-defense-the-davis-enterprise/

https://www.youtube.com/watch?v=IklG_yr7EVU

"Killer Confession: A Double Murder Dialogue in Davis, California" by Lloyd Billingsly (can be found here)