By Joe Holden

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PHILADELPHIA (CBS) — The grim tales of unsolved homicides live in a rolling cabinet on the second floor of the New Castle County building. Some cases date back decades.

They are echoes of the past growing fainter as time passes. But embracing technology to develop fresh leads and solve cases turns out it’s as basic as a game of cards.

Credit: CBS3

“When we met with DOC, we said how many decks of cards do you go through a year,” Detective Brian Shahan recalled. “They said anywhere from about 8,000 to 8,500 decks.”

Shahan, of the Cold Case Squad referenced “DOC,” as in Department of Correction. Inmates at Delaware facilities, for a month now, have been playing cards printed with cold case victims.

“Those are the only decks of cards that they sell in the prison and it’s self-funded,” he said. “Once an edition is done or over for the year, they put 52 more cases and it just keeps going.”

Credit: CBS3

The five of clubs in one deck is the victim of a fatal beating the Garfield Park section of New Castle. Her name was Grace Harmon. Her killer remains in the shadows — a person unknown to the police.

“This was planned, this was targeted,” Shahan said. “We were hoping some people were still around.”

Connecticut has a similar program. Cold case clearance rates improved by 10 percent. Locally, the program is the work of New Castle County, Wilmington, Delaware State Police and Crimestoppers.

In a month’s time, five tips have been generated.

Perhaps it’s enough information to add one of the cases to the closed cabinet.