Jack Daniel McCullough filed an appeal last week. He was found guilty in 2012 and sentenced to life in prison for the murder of Maria Ridulph, 7, in December 1957 in Sycarmore, Ill.
In a brief filed last week, McCullough's lawyers said there was no forensic evidence linking him to the crime. The case against him included an "inconclusive" statement by his dying mother while she was heavily drugged and "innoccuous" statements from McCullough himself.
"The evidence against Jack McCullough was so unreasonable, so improbable, and so unsatisfactory as to create a reasonable doubt that he was responsible for a 1957 murder, kidnapping, and abduction of an infant," Paul Glaser, a public defender representing McCullough for the appeal, said in court documents.
Maria's body was found 120 miles away months after she vanished from Sycamore, a small city in a rural area 55 miles northwest of Chicago. The case attracted a lot of attention at the time -- FBI Director J. Edgar Hoover was concerned -- and when McCullough was arrested decades later.
CNN did a series last August titled "Taken: The coldest case ever solved."
McCullough, now 74, was named John Tessier when he lived in Sycamore. He later moved to Seattle and changed his name.
At the time of his arrest, he was working as a security guard in the Seattle retirement community where he lived.
The investigation was reopened when his half-sister, Janet Tessier, reported statements her dying mother had made to Illinois State Police.