The Killing Season (2016 ) "The Killing Season" from Executive Producer Alex Gibney follows documentarians, Joshua Zeman (Cropsey) and Rachel Mills as they investigate one of the most bizarre unsolved serial killer cases of our time -- ten dead sex workers discovered on Gilgo Beach, Long Island. Authorities believe these killings are the work of the Long Island Serial Killer, who after five years remains at large. Forging relationships with cyber-sleuths, journalists and victim's families, Zeman and Mills uncover connections that suggest Long Island is just the beginning.