Thank you Amanda! I'm from South FL and was thinking the same thing!
Jupiter and Juno beach are not really high-crime areas, so I'm thinking that maybe you are mixing up some J-names. In fact, Jupiter and Juno (South FL- and on the border b/w Palm Beach and St. Lucie counties I believe) are fairly small and quiet towns that you tend to "drive through" on your way to somewhere else.
I grew up in Ft. Lauderdale and lived in an ungated community. Many of my friends lived in gated communities. Of course there is crime in an urban setting, but people are not getting mugged on the streets! It's not that hard to break into a gated community... hop the fence, get to know the security guard, etc. Seriously, the "guard" at my friend's house knew my car and never even called them to say I was headed in, just waved and let M. through.
How can you tell if they are safe locations? Call the local police station and ask. Bottom line, if you are paying more in rent, you will probably be in a "nicer" location. Follow the same safety rules you follow in your home. Keep the doors locked, don't let strangers into your home, don't go somewhere alone at night without telling someone you are going out.
My great aunt lived in Port St. Lucie and it is a beautiful, quiet little town. It's about 30 minutes North of where you are looking at this point, so consider that as well.