The police generally carry sidearm pistols. There are also lots of plain clothed police with pistols stuck in the pants. They extort money from the locals, and occassionally but rarely from tourists, although this is becoming less common. They are generally not into using unnecessary force. They treat hookers as good sources of extortion money. They do keep the peace and investigate major crimes. In fact, they tend to lock up every local in the area of a big crime, and often their families too, during investigations, often for days, even weeks.
I don't blame individual policeman, but I think the justice/police in the Dominican Republic have their priorities a little mixed up.
A couple nights ago, the police were busy arresting every other Dominican in sight for being in the tourist area at night. They were loading them up in the back of pickup trucks, 20 at a time. Sure, most of the locals were out to make a buck or get a free drink or sandwich, one way or another off a tourist, which is 90% of the draw of the nightlife in that area. If I wanted to hang out with a bunch of tourists I'd stay at an all-inclusive.
At the same time, there was a 6 year old boy, no shoes, dirty, curled up on the sidewalk on his side, kind of whimpering and trying to sleep. It was about 1am and the police were right out front. I walked over to the policeman driving the truck and pointed out the small boy and asked how he could drive by and ignore the situation and asked if he could do something about it. He just threw his hands up in the air and drove on down the street.
It seems to be a higher priority to go around arresting people who are not actually doing anything wrong or for "potential crimes", 95% of whom will be released in a day or so without being charged with anything yet have to pay a "fine" or spend even more time in jail, and putting the local businesses out of business, than it is to help a very small child left to cry and sleep in the gutter.
A crowd watched as all this happened. Eventually, a guy sellng flowers picked the child up and took him away, where, I do not know. A few locals commented that the police are not the friend of the local people. That night, the police were the terrorists.
So, what are the police about in the Dominican Republic? They are about protecting the interests of those in power. That includes protecting the tourists, which bring money to those in power. It also means doing what it can to extort money from the weak, oppressing the small businesses in favor of the big powerful all-inclusives, and forcing the morals of the church on the public. It means acting as judge, jury, and prosecutor on the spot.
Often crimes can still be bought out of, unless they become high profile. The police are unlikely to arbitrarily mess with anyone likely to have the money or connections to fight back, and that means that tourists and rich people are generally safe.
They do make the streets safe, but at the cost of individual rights (Cuba style).