Historic photos used as evidence in a string of burglaries in Colorado may have ties to Philadelphia and police are asking for the public's help in getting them back to their rightful owner.

The pictures, which date back to the Civil War era, were found in an old tin and were used as evidence against two men convicted of burglarizing storage units in Jefferson County, Colorado, according to News 9, an NBC affiliate in the state.

For the past two years, evidence technician Kim Van Norman has been searching for anyone who recognizes the people in the 140-year-old photos, most of which were taken in Philadelphia's Tacony section.

Along with the pictures, envelopes addressed to an Emma Stull, including a pension check for her husband Richard, was also inside the tin, said Van Norman. A poem, written by one of the couple's daughters, Lily, was also found.

"We were able to trace their children and who their children married. They seem to have stayed in Pennsylvania, as far as we can tell," she said.

Van Norman and her co-worker used census records they found on the Internet to trace some of the Stull family tree, but have come to a dead end.

"The problem is, when you start on your own family tree, you know the facts and can go forward from there. We’re kind of working backward," Van Norman said.

The determined duo are hoping that will the help of the web, news and social media, they'll be able to find the family and get these photos home where they belong.

"I'll never give up," said Van Norman. "I'm determined to find this family."

Anyone who recognizes the people in the old photos is asked to contact Kimberly Van Norman at 303-271-5655.