Detailed Explanation
The "killer" in Silo isn't a single person—it's the system itself. The Judicial division, led by figures like Robert Sims, identifies threats to the silo's order. IT controls information and the suits used for "cleaning"—when someone is sentenced to go outside. The genius of the show is revealing that multiple people are complicit in murders disguised as suicides, accidents, or the ultimate punishment: being sent outside. Even Mayor Jahns isn't safe when she becomes inconvenient.