This paper examines how extremists who commit crimes are different than non-offending extremists (individuals who have an extreme ideology but do not break the law) and non-extremist violent offenders (individuals who break the law but are not motivated by ideological grievances). This paper provides insight into the risk and protective factors that increase or mitigate the risk of radicalization, extremism and terrorism by focusing on important comparison groups. Data from the Risk and Protective Factors Database (RPFD) was used to examine extremists who break the law, non-offending extremists, and non-extremist violent offenders. Variables tested included demographic, socioeconomic status, and specific individual characteristics (e.g., abuse and psychological concerns, family relationships, peer associations, employment history, criminal history, extremist history, and social life), Internet usage, and pro-social factors such as employment, drug and alcohol rehabilitation, military service, the development of long-term emotional relationships, including marriage, friendships, and childbirth. There were a large number of differences. For example, criminally-offending extremists had more trouble making friends, were more likely to experience negative life transitions, have a mental illness, have a criminal record, and blame a person or collective for their grievance compared to non-offending extremists. Extremists offenders were also less likely to have delinquent peers, use drugs, and demonstrate impulsive behaviors, but more likely to have negative life transitions, demonstrate status-seeking tendencies, and blame others for their grievance compared to non-extremist violent offenders. The results should interest law enforcement officials, other local leaders, and policymakers working to develop innovative solutions for mitigating the domestic pathways to terrorism.