In 2012, a team of US air marshals forced a Delta Airlines overseas flight to return and evacuate because two passengers were thought to be working as a terrorist team, which proved to be false after investigation. This incident plus two other on-plane psychological meltdowns of in-flight personnel are alarming reminders of the snap decisions that are currently made without much guidance to inform such threat assessments. Preflight security measures have addressed many of the post-9/11 threats of terrorism. Nonetheless, successful and thwarted acts of terrorism and reconnaissance response probes have fueled a growing need for homeland security, military and public safety personnel's reflexive instincts to engage, ‘what if’ as a guiding principle in threat assessments. There is an elusive nexus between timely intelligence gathering, acts of terror and understanding the mindset of a terrorist. An internalized homeland security decision-making approach to ‘think like a terrorist’ is instructive in coming up with actionable information for many contraterrorism efforts. This article raises several issues related to the mindset of a terrorist. Such mindset is reviewed from two traditional theoretical frameworks (that is, criminological and psychological theories). The article also explores the applicability of these theories to public safety from a risk assessment perspective. The article concludes with implications for public safety research, practice and training.