Curbing Chicago crime, one jigsaw cut at a time

As grassroots groups look for new ways to prevent crime, they are focusing not only on at-risk individuals but increasingly on entire neighborhoods.

Shawn was at home, scrounging for change, when he heard the sudden crack of gunshots. Outside, he found a young man lying on the sidewalk, surrounded by neighbors. It was his best friend, Brandon. They lived just a block apart and often spent the night at each other’s houses. They sometimes went out together to buy loose cigarettes, hitting up passersby for quarters.

Now Brandon, not yet...