You can focus on cybercrime w/o an IT background, but understanding some basics will help you so very much (as well as providing a little more credibility).
21 is not too "old" to learn IT, or anything else, for that matter. You should focus on your masters first, and if your concentration level allows, take a couple of community college courses on IT basics.
But it's not critical.
You should also research fake ID's, anonymity processes, money laundering, the Darknet (and it's markets), and the connection between organized crime and terrorism.
Here is my reference database with "cybercrime" tagged; I hope that helps