Serial murderers can spend decades in prison awaiting execution, natural death, or parole. Few researchers have examined how these people fit into prison subcultures in the United States, but these studies indicate that serial murderers have unique experiences. Prison administrators must find a way to prevent these people from harming more victims while protecting them from targeted violence. In this chapter I use data from the Consolidated Serial Homicide Offender Database, misconduct records from a large Midwestern state, Mortality in Correctional Institutions: State Prisons, 2001–2019, the National Corrections Reporting Program, 2000–2019, and interviews to examine the prison records of people convicted of multiple murders. This may shed some light on important questions about how serial murderers live (and die) in prison.