Akinola’s PhD is in organizational behavior. Here’s the area of that PhD:
The doctoral program in Organizational Behavior trains scholars who are able to draw on the concepts and methods of psychology and sociology in conducting research on behavior and management within complex organizations.
Her dissertation, Deadly decisions: An examination of racial bias in the decision to shoot under threat, is pretty directly related to organizational behavior - the behavior of people within complex organizations, namely police departments. (She also appears to have been studying social psychology at the same time, maybe in some sort of concurrent program, which would probably influence the shape of her dissertation.) I’d imagine that someone in a similar department could do a similar dissertation, but I don’t think one could get a random management or marketing PhD and do criminal justice research unless that research was about how criminal justice is related to management or marketing or something.
Also - and importantly here - Dr. Akinola’s work after her PhD dissertation has nothing to do with criminal justice. Her overall research seems to be focused on how stress and stress responses influence people’s behaviors and performance within workplaces; it seems as if the police department was simply one example of that rather than her research agenda being actually focused on criminal justice. If you want a career doing criminal justice research, you’d have to go to a department that actually has a focus on that OR do some kind of interdisciplinary research at the intersection of X and CJ (in which X is the department that you’re in).