For CPTED professionals, getting accurate and representative crime data is ALWAYS problematic. Comparative crime data (e.g. crime rate/suburb) is even more problematic.
A new source of comparative crime data for Perth, Western Australia is the Perth Crime Map.
The only relatively valid, fully-assured crime data is court crime data. The problem for CPTED is that only a tiny proportion of criminal activities reach court. Police reported crime incident data offers a bigger picture of the crime situation but at the expense of less validity.
In Perth, Western Australia, Nick Lilleymen has used police reported crime incident data and census data to independently create a map of comparative crime in Perth metropolitan suburbs - http://www.perthcrimemap.com
Our compliments to Nick for producing and maintaining this Perth Crime Map. It makes things much easier for metropolitan CPTED professionals in Western Australia to adopt an evidence-based approach to designing CPTED interventions. Previously, without the crime data equivalent of something like the NSW BOCSAR website, WA police crime incident data has been difficult to use comparatively.
The challenge of the Perth Crime Map for CPTED professionals is awareness of its relative accuracy. Police recorded crime incident data is noted worldwide for being creatively shaped by a variety of political and other factors. In parallel, the demographic data used in the Perth Crime Map is relatively old (2010), and many Perth metropolitan suburbs are subject to significant change. Combining these two potentially inaccurate data sources to get crime rates presents some concern because it multiplies their errors.
For CPTED practitioners in Perth, however, there is nothing better currently than the Perth Crime Map unless one creates one's own data.
Here is hoping Western Australia funds its police to create a Western Australian version of the excellent NSW BOCSAR crime research data service, or the UK's data.police.uk website. In the meantime, the Perth Crime Map offers a useful comparative crime data resource.