After a year and a half of searching, investigators found the skeletal remains of Shannan Gilbert on Gilgo Beach."What was the ultimate stunner in all of this is that they believed -- and still do believe -- that Shannan Gilbert was not murdered. That Shannan Gilbert died in an accidental drowning," recalled reporter Josh Einiger.A few years later, Shannan Gilbert's mother, Mari Gilbert, who is credited for the discovery of the Gilgo bodies because of how she pushed for her daughter's search, is found stabbed to death in her apartment.

Chapter 6 of "Eyewitness to Gilgo Beach" drops Thursday, Feb. 22. Follow the podcast and never miss an episode. Learn more about your ad choices. Visit megaphone.fm/adchoices