I am increasingly liking murder maps. They are simple, straight forward and easy to interpret. They are the quickest way to understand where the safer and less safe neighbourhoods are in major towns. Something that the people who live there probably know but essential risk assessment information for the intrepid traveller.
The first map shows murders in Washington DC, USA 2005-9, the link is here. The designer has helpfully shown which area is included, which means that it is obvious that there are almost no murders west of the Potomac River and many to the east
No murder housing near the Cathedral west of the Potomac River
Many murders housing east of the Potomac River