From the Bureau of Justice Statistics, these data are available at the city level only. However, they provide a fuller and more completel picture of law enforcement trends for the city than the UCR reports alone.

Only available at the city-wide level, the Bureau of Justice Statistics provides Homicide Trends from 1985-2005

This is not an official site. However, it takes the data from the Philly Inquirer for the city in 1999, and for West Philadelphia from the Almanac and maps it in Google maps. A neat site, worth looking at.