Following the hearing, it is expected Grimes will impose sentence.
In May, a jury found Martin, 50, of New Geneva guilty of all charges, including first-degree murder, rape and aggravated indecent assault. The panel also recommended that Martin be put to death for his crimes.
He raped and strangled Gabrielle Bechen on June 13, 2006, when she visited the Dunkard Township horse farm where Martin worked. He also buried her body and all-terrain vehicle, hampering a massive search to find the missing girl.
The formal sentencing hearing had been scheduled for Thursday.