How useful would a doctorate in criminal psychology be?

I want to work with police officers and help them with suspects and/or interview criminals to see why they do what they do. My second and third choices for college would be going to a flight school to get my pilots, or going to a law school to become a lawyer. I don’t know which one is the most useful.
Here’s some information on what a criminal psychologist does: https://www.verywell.com/criminal-psychologist-a-career-profile-2795649
I just graduated last year (2016) and due to financial setbacks that occured during my junior/senior year, I couldn’t go right into college so I’ve had extra time to think about what I want to do.