Richard Schmack, DeKalb County state’s attorney, said Jack D. McCullough, 76, of Seattle, could not have abducted and killed 7-year-old Maria Ridulph in 1957, according to a DeKalb County State’s Attorney Office news release Friday.

The state’s attorney’s declaration comes at the conclusion of a six-month, court-ordered investigation with the Illinois State Police. The 55-year-old case is one of the United States’ longest to be solved cold cases. On September 14, 2012, McCullough was found guilty of murder, kidnapping and abduction of an infant. McCullough’s murder conviction was upheld by the Second District Appellate Court, according to an Illinois State Police news release.

Schmack said it was an “impossibility” for McCullough to have been in Sycamore during the time of the crime as he was found to have been making a phone call in downtown Rockford. The shortest distance from Sycamore to downtown Rockford is 35 miles, Schmack said in the news release.

“I truly wish that this crime had really been solved, and her true killer were incarcerated for life,” Schmack said, according to the news release. “When I began this lengthy review I had expected to find some reliable evidence that the right man had been convicted. No such evidence could be discovered. Compounding the tragedy by convicting the wrong man, and fighting further in the hopes of keeping him jailed, is not the proper legacy for our community, or for the memory of Maria Ridulph.”