​How a stretch of a South Side Chicago neighborhood rid itself of shootings

CHICAGO -- It is no secret Chicago has a crime problem: murders this year are up 21 percent. But in one part of town, they're down 14 percent.

The turnaround has the sounds of childhood making a comeback on Yvonne Marshall's block.

"All you hear is kids laughing and playing," said Marshall.

Yvonne Marshall CBS News

The grandmother of five credits desperate pleas on plywood that read, "Don't shoot. Kids at play. Let the kids grow up."

The signs showed up on Bishop Avenue in late May after 4-year-old Jacele Johnson was shot in the head nearby.

The little girl survived, but in the last five years more than 300 children have been killed in Chicago. Marshall attended eight of their funerals.

She said she used to hear gun shots in her neighborhood at least once or twice a week. But since the signs, there hasn't been a single shooting on these two blocks.

Kids stand next to signs advocating for a stop in gun violence in Chicago CBS News

The calls for peace came from former gang members who put up the signs.

"We felt it was needed," said Joe Walker. "So many kids losing their lives at a young age."

Walker, Dwan Brown, and their friends grew up in the area. Now they have children of their own.

"We were trying to make it a surprise for the neighbors too, and when we put them up they was like unbelievable,'" said Brown.

It may have been their innovation, but the motivation came from a meeting with Chicago police superintendent Garry McCarthy. He routinely calls in gang members and parolees after shootings.

A sign, advocating for an end to gun violence, is posted outside a Chicago home CBS News

"We introduced them to the concept of group accountability," said McCarthy.

That means if a kid gets shot, police say everybody in the area will feel the heat.

"We can't be accountable for what's happening on any other block but we can be accountable for what happens over here," said Brown. "So what can we do different -- the signs."

With all the high tech resources at the police's disposal, it's these crude plywood signs that neighbors say have made the difference.

"I don't care if it was done in crayon, if it's spray paint on a piece of cardboard and it's effective, let's get more spray paint and cardboard," said McCarthy.

The hope here is that the signs spread to other troubled blocks so kids can be kids and keep playing outside.