I haven't found robbery/general crime stats, since international comparisons are tough, but, when it comes to murder (I assume that murder is likely to be roughly proportional to other crimes):
New York City
In 2004 there were approximately 570 homicide victims, recorded by the New York City Police Department (
Source) . According to the US Census Bureau there were approximately 8.1 million people in New York City in 2003.
Therefore in 2004 New York City had a homicide rate of
7 murders per 100,000 population.
Sydney
In 2005 there were 49 recorded victims of murder in Sydney ([url=http://www.lawlink.nsw.gov.au/lawlink/bocsar/ll_bocsar.nsf/vwFiles/RCS05.pdf/$file/RCS05.pdf]Source[/url). There was an estimated 4.26 million people living there at the time, giving a total of 1.15 murders per 100,000.
Melbourne
It has proven to be difficult to locate data for Melbourne. The Victorian Police publish
Region, Division, LGA Statistics 2005-06. This report states that the homicide rate per 100,000 people in police Division 1 (which most closely matches Melbourne) was 4.6 in 2004-05 and 4.7 in 2005-06. However, comparing these figures to the published ABS Recorded Crime data indicates that the homicide figures reported are actually ‘homicide and related offences’ (murder, attempted murder, manslaughter and driving causing death).
Regardless of all this, this sucks for JP and I hope that the thief gets caught.