Property Taxes Seem to be increasing near Pittsburgh, PA

[D'Andre Byers]

I'm fairly new to RE investing and so I've just been browsing zillow and realtor.com a lot and getting my feet wet with all of the calculators. I'm from about an hour north of Pittsburgh, PA and the market where I'm at just doesn't seem to be taking off as much places closer to the city. However, as I start moving closer to the city (aprox. 30-35min away from the city) there are some decently priced houses that are selling. As I'm looking around I'm noticing that most of them have one huge thing in common and that is a crazy spike in property taxes. For example, one property went from $1,851/yr to $7,558/yr. I'm assuming this is what's prompting people to move from their homes. But I have a few questions in relation to this happening.

1. Why would this be happening at such a dramatic rate?

2. Can I expect these people who are selling to move further north from the city to get away from these taxes? I've been hearing a lot of talk about how the suburbs of Pittsburgh keep moving further and further north away from the city. 

3. Where can I go to find out how property tax trends work? (if there is such a thing)

Any info on this would be helpful.