The attorney for a southern Illinois man who pleaded guilty to first-degree murder in the 2013 stabbing death of his 7-year-old niece has filed a motion seeking to overturn the man's sentence.

Justin DeRyke was accused of killing Willow Long in September near her home about 100 miles northeast of St. Louis.

After the 23-year-old DeRyke pleaded guilty, he was sentenced in March to natural life in prison. The Effingham Daily News reports Public Defender Scott Schmidt has asked the Effingham County Circuit Court to reconsider the sentence.

In his filing, Schmidt noted the Illinois Supreme Court in 1998 found the natural law statute unconstitutional.

State's Attorney Bryan Kibler says if DeRyke's sentence is overturned, there are other provisions under which the man could receive a natural life sentence.

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