This week's episode includes two mass murderers striking at random and the mysterious death of Rodney Marks. 
Jessica's sources: 
https://www.nytimes.com/1973/11/08/archives/nine-are-found-slain-in-sixth-mass-murder-case-in-california-in-the.html- no author 
https://www.abc15.com/news/crime/death-row-diaries-douglas-gretzler-executed-after-being-responsible-for-17-deaths-in-az-cal Joe Enea
Jaymie's sources:
https://www.reddit.com/r/UnresolvedMysteries/comments/e0b7ev/did_someone_get_away_with_the_murder_of_rodney/