The jury deliberated for less than two hours before unanimously finding 61 year old Mark Fishler of Dubuque guilty of first-degree murder on Tuesday. Fishler was convicted in the death of 80 year old Berniece Williamson of Dubuque. A conviction on the charge carries a mandatory sentence of life in prison without parole. Williamson was found dead on July 15, 2021, inside her home on Clarke Drive in Dubuque. Authorities indicated that Fishler was the last known person to see Williamson alive. After discharging the jury, the Iowa District Court Judge told prosecutors and the defense attorneys that she would set hearings at a later date.