I live in St. Louis, statistically the most dangerous large city in the USA, and ride my bike around all the time. However, I try to avoid the worst neighborhoods completely, and the questionable ones after dark. I have no knowledge of Camden (other than it is statistically dangerous). Perhaps scoping out the ride in your car first is a good idea. Another would be to re-route around Camden or through the "better" parts. Or simply ride as fast as you can for those 4 miles and don't look at anyone...

I've also gone through E. St. Louis on my bike before with a friend (we made a wrong turn). While no one mugged us, we were practically stared out of town. Not something I would do again...