The detectives who remember the children

Mrs. Johnson knows witnesses refuse to talk, and said she dreams of her son.

"And he's telling me from the grave, 'Mama, don't let them get away with this,'" she said.

Sometimes, witnesses do talk. It's one way that cases get made. But often they don't, and without witnesses willing to testify, it's difficult for detectives to persuade prosecutors to file murder charges.

To be a homicide detective in Chicago is to live with frustration. They wait for lab results that could take more than a year. They wait for leverage on witnesses.

Sullivan told a story of a gang member who wouldn't cooperate, even though his own brother was shot dead beside him by members of their own gang.

"He sees the shooter. It's a mistaken shooting. It's their own gang guys shooting down the street. He realizes it. He won't tell us," Sullivan said.

On the TV shows, the brother talks. In Chicago, the brother handles things himself. Another statistic is made. And the detectives talk to the mothers of the imperfect dead.

"And that mom thinks that kid's the greatest thing since," Sullivan said, his voice trailing off. "His sister loves him. The boys love him. But when you look at what he was to society, it's …"

"Everybody has a mom," said Moore-Grose, finishing for him.

A mom is the reason we met. It was a reader of this column, Kathy Cummings, who wrote to me to praise the detectives for staying on the case of her son, Dwoyne Baker, killed in 2010.

Baker was shot near 79th and Brandon. There are several other victims on or near that corner in the detectives' caseload — like Nazia "Peanut" Banks, whose death was barely noticed by Chicago because it coincided with the NATO summit last May.

"He was a little boy," said Moore-Grose. "Some 12-year-old boys, you think they're 15, 16. This kid was just a little scrawny little kid. He had a little squirrel on his shirt."

Twitter @John_Kass