Many municipalities provide open data on crime statistics.
This project tries to leverage that data and show patterns.
The direct source for this data is OpenDataPhilly
Below shows Philadelphia Center City crime
# Here's a quick way to get the data into R
library(RCurl)
File <- getURL("https://raw.githubusercontent.com/mchirico/crime/master/data/philly_crime.csv")
d <- read.csv(text = File,header=TRUE,stringsAsFactors=FALSE)
wd<-function(x) as.POSIXct(strptime(x, '%Y-%m-%d %H:%M:%S',tz='GMT'))
d$mdate = wd(d$DISPATCH_DATE_TIME)
# Remove na's
d=d[complete.cases(d[4:5]),]
For a more detail, see Analyzing Philadelphia Crime Data