Mass shootings have received widespread media attention due to their extreme violence. People who report greater belief in pure evil (BPE; the tendency to attribute harmdoing to dispositionally sadistic individuals) generally favor harsher criminal punishment, regardless of whether criminals exhibit stereotypically “evil” traits. We examined whether BPE predicted evaluations of gun violence perpetrators despite different situational factors related to the shooter's and crime's circumstances. An online, national sample (N = 275) read an allegedly real USA Today article about a mall shooting. We manipulated the shooter's evilness; whether the shooter exhibited a brain tumor, which could have accounted for his violent behavior; and, whether the event was a mass shooting. Results showed that individuals who reported greater BPE demonized, dehumanized, and punished the shooter more across all experimental conditions. Thus, results indicate that stronger pre-existing beliefs in pure evil may override key situational information when punishing violent offenders.