Donald Trump kissed the firefighter helmet of a man who was shot and killed during an assassination attempt at a rally in Pennsylvania on Sunday, 14 July.
Corey Comperatore, 50, died shielding his wife and daughter as a gunman opened fire on the event in Butler.
The former president appeared on stage with Mr Comperatore's uniform during his nomination acceptance speech at the Republican National Convention on Thursday night.
Mr Trump added that $6.3 million had been raised for families of those injured in the shooting.