This is the million-dollar question and with most of the heavy questions, there is not a black and white answer. In short, crime statistics are a decent indicator of the likelihood of a particular crime happening to you in an area.
There are a ton of factors involved in how accurate and predictive the stats can be. It is important to look at how the data was collected, try and find the year over year data, and check for new legislation or fighting crime campaigns in the area.
Something you will want to take into account (most sites do it these days) is to look at ratios rather than total crime numbers. Crime ratios numbers derived from total crime figures and then simplified into a fraction. That fraction is normally displayed in the form of “1 out of every 100,000 people”, which allows you to compare more accurately amongst other areas.