Autistic people's perceptions of their interactions with criminal justice professionals are predominantly negative; however, little is known about the state of interactions on a global scale. To further understanding, a comprehensive stakeholder questionnaire was created. Aspects of reliability and validity including evidence for test content and internal structure were gathered using expert reviews, cognitive interviewing, pilot data collection, and a larger data collection effort (N = 1618). Data was gathered from the autism community through perspectives of parents/caregivers as well as from self-reported autistic adults. Criminal justice professionals included law enforcement officers, corrections professionals, probation and parole officers, forensic psychologists and legal professionals. The scale development process was detailed in order to sufficiently document the initial psychometric evidence and share the steps taken to gain diverse stakeholder input. This study is a critical first step in generating further information to facilitate policy and program development with wide applicability.