The spectator killed in the shooting that targeted former president Donald Trump has been identified as Corey Comperatore, a 50-year-old firefighter and father of two who died shielding his family from the gunshots.

Comperatore "died a real-life super hero," one of his daughters, Allyson, said in a Facebook post after the attempted assassination of Trump at a rally in Pennsylvania on Saturday.

"He threw my mom and I to the ground... (and) shielded my body from the bullet that came at us," she continued.

She described her father as "the best dad a girl could ever ask for," someone always ready to help and quick to "make friends with anyone."

The governor of Pennsylvania also described Comperatore as a hero and said state flags would be flown at half-staff in his honor.

"We lost a fellow Pennsylvanian last night," Governor Josh Shapiro, told reporters.

He said Comperatore was a churchgoing firefighter who "loved his community and most especially... his family."

"Corey was an avid supporter of the former president," Shapiro added, "and was so excited to be there last night."

Shapiro called Saturday's shooting, in which Trump was bloodied but survived and two other spectators were wounded, "shocking, for this Commonwealth (state) and the country."

The other victims were identified as David Dutch, 57, and James Copenhaver, 74, according to Pennsylvania State Police on Sunday.

Both were also from Pennsylvania, and said to be "in stable condition."

The shooter, identified as 20-year-old Thomas Matthew Crooks of nearby Bethel Park, was killed by a Secret Service sniper.

A GoFundMe page created to raise money for the Comperatore family had received donations of nearly $650,000 as of 7:00 p.m. (0000 GMT).