Just because it was used by a peace officer doesn't mean it is well used, only well worn.
As far as difficulty racking, I will offer you up a technique that could make it easier:
Assuming you are right handed, cup your left hand over the top of the slide and grip tightly. Instead of trying to pull back on the slide with your left hand, hold your left hand steady in place and push the firearm forward quickly with your right hand. Your right arm's tricep and chest will have more strength than your left bicep. Pushing aggressively will do better than a slow push.
Hope this helps. The G19 is a great gun.