A guard to have a safe visit?
?? 
There are public displays of security and police in the DR. it's not an unsafe place in general, rather a place that really wants to protect it's tourism industry. If a local gets caught messing with a tourist, they tend to not take that lightly if you know what I mean.
It isn't out of the ordinary to see police on a street corner standing there with a shotgun. It's about 99% for show, remind the locals the consequences of bad decisions and make tourists feel safe.
I spent a week there, great place to visit and I would love to go back.
