Question: Is it permissible for a Jew to eat meat that isn't treif or forbidden flesh if it was not purchased from a kosher butchery? I was told by a Muslim friend of mine that non-[halaal](http://en.wikipedia.org/wiki/Halal#Food) meat (except pork) isn't haraam (forbidden) even if it wasn't slaughtered with a prayer as they do. Is this true in Judaism as well?

Answer: 
No. A kosher animal must be specifically slaughtered and prepared according to Jewish laws in order for its meat to be kosher. 

These laws are very specific, governing the knife used, the method and stroke of the knife, the method for soaking/salting properly, and checking the innards for defects which would render the animal unkosher. If any of these laws are not followed, then the meat is not kosher. 

As such, Jews will only buy meat from an individual/store/company that they trust to follow these laws.
Kudos to both answers above; just one more point: after the ainmal is slaughtered by a Jew according to Jewish law, the meat is then inspected, soaked, and salted; then it can be packaged in a reasonably tamper-proof container and shipped off and sold at any general supermarket. So you don't have to go to a "kosher butcher shop" per se.