WHO KILLED MARY NETHERLAIN?

I found the documentary very interesting at the link, https://ne-np.facebook.com/CriminallyListed/videos/criminally-listed-donna-frislie/345680906889254/?__so__=permalink&__rv__=related_videos. After analyzing the connection between the killing of Donna Marie Frislie and that of Cheri Jo Bates in Riverside in the land of citrus fruits, thanks to the documentary, a connection is reached with the brutal killing of Mary Netherlain, massacred by several stab wounds