Interpol. There are currently 186 cooperating countries, Cuba included, meaning if you commit a serious crime and flee, you can get caught in most every country in the world.
List of countries:
You'd either have to go to a non-participating country (which I can't even find one), or change your identity. Either lose or gain weight so your face looks different, possibly take some growth hormone and/or major doses of testosterone in order to change the facial structures: jaw, nose, forehead, ears (sometimes). Plastic surgery could work, even something minor, though changing bone structure is very important.
If it's not to crazy, like you're not worldwide top ten criminal, then a fake ID is a good idea, and you get what you pay for so be willing to spend some money. Unfortunately, it will take some time to make contacts to get the new ID, and of course most of these suppliers are located in larger cities which poses a problem, especially if there is a CCTV facial recognition system in use.