BackgroundIn recent years, the delivery of evidence-based therapies targeting posttraumatic stress disorder (PTSD) has been the focus of the Departments of Defense in countries such as Canada, the Netherlands, and the United States. More than 66% of military members continue to experience symptoms of PTSD that significantly impact their daily functioning and quality of life after completing evidence-based treatments. Innovative, engaging, and effective treatments for PTSD are needed. Multimodal motion-assisted memory desensitization and reconsolidation (3MDR) is an exposure-based, virtual reality–supported therapy used to treat military members and veterans with treatment-resistant PTSD. Given the demonstrated efficacy of 3MDR in recently published randomized control trials, there is both an interest in and a need to adapt the intervention to other populations affected by trauma and to improve accessibility to the treatment.ObjectiveWe aimed to further innovate, develop, and validate new and existing hardware and software components of 3MDR to enhance its mobility, accessibility, feasibility, and applicability to other populations affected by trauma, including public safety personnel (PSP), via international collaboration.MethodsThis study used a modified Delphi expert consultation method and mixed methods quasi-experimental validation with the purpose of software validation among PSP (first responders, health care providers) participants (N=35). A team of international experts from the Netherlands, the United States, and Canada met on the web on a weekly basis since September 2020 to discuss the adoption of 3MDR in real-world contexts, hardware and software development, and software validation. The evolution of 3MDR hardware and software was undertaken followed by a mixed methods software validation study with triangulation of results to inform the further development of 3MDR.ResultsThis study resulted in the identification, description, and evolution of hardware and software components and the development of new 3MDR software. Within the software validation, PSP participants widely acknowledged that the newly developed 3MDR software would be applicable and feasible for PSP affected by trauma within their professions. The key themes that emerged from the thematic analysis among the PSP included the desire for occupationally tailored environments, individually tailored immersion, and the applicability of 3MDR beyond military populations.ConclusionsWithin the modified Delphi consultation and software validation study, support for 3MDR as an intervention was communicated. PSP participants perceived that 3MDR was relevant for populations affected by trauma beyond military members and veterans. The resulting hardware and software evolution addressed the recommendations and themes that arose from PSP participants. 3MDR is a novel, structured, exposure-based, virtual reality–supported therapy that is currently used to treat military members and veterans with PTSD. Going forward, it is necessary to innovate and adapt 3MDR, as well as other trauma interventions, to increase effectiveness, accessibility, cost-effectiveness, and efficacy among other populations affected by trauma.