MashGet

In a faceless building by the freeway, George Tiller performed thousands of abortions a year. Some of his patients were well advanced in pregnancy -- seven, eight, even nine months along. And so his clinic became a battleground.

Fewer than 1% of all abortions in the U.S. -- perhaps 1,000 a year -- are performed late in the second or third trimester. But they are a potent symbol of a deep cultural divide. In the abortion debate, little elicits more emotion than the idea of killing a viable fetus, weeks or even days from birth.