I would like to become a Military Interrogator. What Career path should I follow?

[grumpy]

Would I need a Doctorate in Psychology or do I need a Major? Which Branch would be the best to join?

 

[Mr Puma]

You would have to qualify to join the Intelligence branch of whichever service you join. That means that you would have to score in the top ten percent on the ASVAB tests, plus have a squeaky, and I do mean squeaky, clean background and speak or are able to learn a foreign language.

 

[Stevie]

Military Intelligence? MI usually does the most interrogations of terrorists and other criminals... you would just need to enlist with that MOS.
You could take courses in homeland security ... but you could enlist and receive their training...which transfers to college courses.