Advice on joining Criminal Investigation Division (CID), OSI, NCIS?

I am currently serving active duty in the Marine Corps, with the Marine Corps Embassy Security Group. Will have completed a bachelor's degree in law enforcement administration, in December 2015. T/S Clearance holder. I am hoping to transition, or LATMove into the Marine Corps' Criminal Investigation Agent MOS (5821). If that option is not available I would certainly entertain the possibly of transitioning services, to join up with the Air Force's Office of Special Investigations, Army CID or NCIS.

My goal overall is to remain on active in the military while working in the federal law enforcement community. All information and input is welcome and thank you in advance for sharing!