The current study examines potential serial homicide offenders (SHOs), a previously unacknowledged offender group comprised of aspiring and probable SHOs, and compares them to successful SHOs. Data on 17 aspiring, 46 probable, and 16 successful SHOs were collected. The study results indicate that potential serial killers share more in common with successful SHOs than they do with one-off homicide offenders. While there is overlap among these groups, there is insufficient evidence to suggest discreet transitions among categories or that being a potential SHO is the final step on a pathway towards becoming a successful SHO. Potential SHOs cannot reliably be thought of as prospective SHOs if all things were equal. An as yet identified factor, such as resiliency, still separates potential SHOs from successful SHOs. Early identification and timely intervention is important to interrupt impending murders by potential SHOs and halt them at this pivotal point in their developmental trajectory.