Amnesia for serious offenses has important legal implications, particularly regarding its relevance in the contexts of competency to stand trial and criminal responsibility. Forensic psychiatrists and other mental health professionals are often required to provide expert testimony regarding amnesia in defendants. However, the diagnosis of amnesia presents a challenge, as claims of memory impairment may stem from organic disease, dissociative amnesia, amnesia due to a psychotic episode, or malingered amnesia. We review the theoretical, clinical, and legal perspectives on amnesia in relation to crime and present relevant cases that demonstrate several types of crime-related amnesia and their legal repercussions. Consideration of the presenting clinical features of crime-related amnesia may enable a fuller understanding of the different types of amnesia and assist clinicians in the medico-legal assessment and diagnosis of the claimed memory impairment. The development of a profile of aspects characteristic of crime-related amnesia would build toward establishing guidelines for the assessment of amnesia in legal contexts.