Law enforcement careers?

Im very interested in going into law enforcement. i just graduated so im trying to figure out what major i want to do. i was going into nursing but ive realized thats not really what i want to do forever. So i was wondering, i don't want to be a police officer, but what other jobs are there? I do want to work with officers but i don't want to be a patrol officer. I would want to be the ones that work in like sting operations, or in investigations maybe. Or the ones that have the drug dogs. But i know to have a K9 unit u have to be an officer for 2-3 years.. Idk.. anybody have any ideas? thanks!