As 72-year-old former police officer Joe DeAngelo’s arrest unfolds in real time, chilling facts materialize that illuminate Michelle’s prescience in her book’s epilogue, “Letter to an Old Man.” Researcher Paul Haynes and true crime writer Billy Jensen try to learn everything they can about DeAngelo. When Patton Oswalt, Jensen, and Haynes connect with survivors and McNamara’s fellow citizen detective Melanie Barbeau, Michelle’s absence is deeply felt. Series finale.