Crime taxonomy · Maps and colour

Raw totals on a map

A map of raw counts that is really a population map.

What it looks like

A choropleth shows totals (cases, crimes, sales) where a rate is needed, so the map mostly shows where people live.

Example

The same data shown honestly: Cases per 1,000 residents show where the risk is actually higher. — **The fix.** Cases per 1,000 residents show where the risk is actually higher.

Why it is bad

Big populous regions always have the most of everything. The map says nothing about risk.
It is one of the most common map mistakes, and AI tools make it by default when given raw counts.
A dramatic title turns the population pattern into a false story about "hotspots".

How to fix it

Map rates (per capita, per household, per km²) on choropleths.
If totals matter, use proportional symbols on a neutral base map instead of filled areas.
Say in the legend exactly what is normalised by what.

When it is not a crime. Mapping totals is fine when the total is the point (e.g. where to send supplies), shown with symbols rather than shaded areas.