Calvin Ushery was sentenced to 40 years in prison for the crime, the Delaware Department of Justice announced Thursday.
Ushery, who is 40 years old, was declared a habitual offender.
The attack happened in September 2022 at Solid Gold Jewelers on W. 9th Street.
Prosecutors say Ushery pistol-whipped the shop owner three times, knocking him to the floor. He then climbed over the counter, stomped on the victim's head several times, and began smashing display cases with a hammer while filling his bags with jewelry.
When the victim started to stir, prosecutors say Ushery struck him in the head several more times - including blows with a hammer - before fleeing with stolen jewelry.
The victim spent a week in the hospital, including four days in Christiana Hospital's intensive care unit, before he was discharged.
Ushery's first trial ended in a hung jury back in Sept. 2023.