Stumbled upon this jewel today. Attached the PDF version for your enjoyment: US DOJ statistics from 2006 (the most recent) detailing response times to certain crimes.
Interesting to note:
If you were the victim of a robbery, you had a 8.8% chance the response time will be greater than 24 hours. Combining all three of the listed non-violent categories, only 1.9% of callers endured waits over 24 hours.
If you were the victim of a robbery, there was a 34.7% chance that the cops responded in greater than 10 minutes, but only a 26.4% chance the cops arrived within 5 minutes of your call.
If you were the victim of any of the 3 listed violent crimes, there was a (combined) 73.4% chance that the police are more than 5 minutes away.
So, just in case a gun hater tries to argue, we have undeniable proof that "when seconds count, the police are just minutes away... or hours... or days..."