In December 2006 the FBI published their estimated crime statistics for the largest cities in the country. The news was not good. The reported number of violent crimes increased nationally by 3.7 percent in the first half of 2006 when compared to figures reported for the first six months of 2005. For the purposes of this analysis, violent crimes include murder, forcible rape, robbery, and aggravated assault.
The good news is that property crimes in the United States from January to June of 2006 decreased 2.6 percent when compared to data from the same time period in 2005.
Here is the crime data as reported by the FBI for the largest cities (100,000 population or more) in Maricopa County. Cities that were not included (Scottsdale and Peoria) probably didn't provide complete data to the FBI in order for them to be included in the report.
You'll see that I have added some calculations to make comparisons easier. For each city I include a number for violent crimes during the first six months of the year based on population for both 2005 and 2006. At the time of this writing, population estimates for 2006 are not available, so I calculated the growth in the cities from 2004 to 2005 and assumed the same growth rate for the year 2005 to 2006. I have not done any statistical analysis to determine the error rate of that approximation; it's just a guess.