Las Vegas Metro issues annual reports of crime statistics, but they categorize crime by type, not area.
Rather than issue blanket condemnations of this or that neighborhood, we recommend that you decide in advance where you’d like to go. This done, log on to Metro’s CrimeMapping application. Set the date range you want to search and, over a map of the Vegas area, icons representing every police call during that period will be superimposed, indicating the exact location and nature of the incident (a lot of them will be in heavily trafficked tourist spots, like the Las Vegas Strip.) For instance, on June 1 there was a "disturbing the peace" call at the intersection of East Naples Drive and Swenson Street. Had you been considering that particular corner, on that particular day, as a place to chill out, armed with this foreknowledge you would have had the chance to reconsider.
In addition, for up-to-the-minute breaking news about any major police activity, plus information like the phone number for the LVFR Bee Hotline (call 702-229-2000 for a 2-minute recording with bee safety tips, following some recent dangerous incidents involving dangours swarms), follow the official @LVMPD Twitter.
This ounce of prevention could save you a pound of cure later.