The crime level in Nicaragua comes down to where you are and your security measures. For example, if you have a very nice car and you park it in a good area with no one to look after it, it could get vandalized. But you could also have the same nice car and park it in a bad area, but with someone to look after it, and nothing will happen.
Compared with Seattle (where I used to live), the crime in Nicaragua is about the same, but Seattle and Nicaragua have different issues. For example, in Seattle, lots of people have guns, while in Nicaragua, you don’t see it that much. I have never heard of an issue of guns in a school in Nicaragua. People in Nicaragua would faint if they heard that. You also don’t hear about a mall or bank shooting in Nicaragua. In Seattle, you will see lots of drugs, while in Nicaragua, you won’t. I keep reading how bad the crime is in Central America, that people are having guns held to their heads, etc. I have never, never been mugged, and I’m "a girl in an SUV," living here from the age of 18 to 30. I have, however, been pick pocketed in the public market, but that could happen in Seattle.
One of the differences about living in Nicaragua is that, in Nicaragua, depending on where you go, it can be a good idea to pay someone to look after your car. If you don’t have someone with you, you just pay a person in the street whose “job” it is to watch the car in that area. The most you would pay is a dollar. If they look at you as a foreigner, they may ask for two dollars, but that’s about it. In Granada and the better area of Managua called Carretera Masaya, I don’t pay to have someone watch my car.
You should always be aware in Nicaragua and avoid going by yourself to isolated places while carrying items like expensive cameras.
The safer areas are the cities, as opposed to the outskirts and the mountainous areas.