Reaper's wisdom is on target and I agree debating gun control is not as productive as other efforts. I don't know if Palau is a good comparison, however. The common component in the violent crime in San Pedro appears to be drugs and related turf battles. Guns or no guns in the hands of law-biding citizens and you will still have this issue.
Reaper is very insightful regarding preventative investment that decreases the likelihood gangs become appealing. However, so long as there is a profit motive well beyond the opportunity provided elsewhere in Belize, the problems will persist.