Ellie discovers a Facebook group for former students of an English teacher named Roger Kaplan , who used to have his students write "love letters" to houses. This makes Roger a primary suspect for the origins of the Watcher's poetic and creepy writing style. Fact vs. Fiction
A major turning point occurs when DNA testing on a letter envelope reveals it belongs to a woman. This immediately places Nora and Ellie under suspicion, but also broadens the field to neighbors like Pearl . The Watcher s01e05
Real-world investigators did find female DNA on one envelope, but it did not lead to an arrest or a breakthrough in the case. Deep Dive Resources Ellie discovers a Facebook group for former students