This question gets posed as new crime statistics for Pittsburgh are released showing a decrease in violent (Part 1) crimes.  Data from the Pennsylvania State Police's Uniform Crime Report shows crime stats, but also contains data on the fifteen largest local police agencies.  Omitting county forces, the five largest municipal forces (measured by full time police officers) in 2010 were Philadelphia (6,734), Pittsburgh (887), Allentown (197), Harrisburg (179), and Erie (173).  That's a total of 8,170 officers in those five cities.

A decade earlier those five cities combined had 8,580 full timers, about 400 more.  Obviously, populations of those cities has changed a bit, so it is more accurate to take a measurement of full time officers per 1,000 people in those two time frames.

All of those rates were down with the exception of Harrisburg, which was up slightly from 3.5 per 1,000 to 3.6 per 1,000.  Probably not very noticeable as the city reported having eight more officers in 2010 than 2000.  Pittsburgh, even with layoffs prior to Act 47 status and changes to post-retiree health care, which affected police, still carries roughly the same officer per 1,000 people with 3.1 in 2000 and 2.9 in 2010.