Daniel Hernandez checked pulses, and saw that one man was already dead. Then he saw Giffords who was lying on the sidewalk. Using his hand, he applied pressure to the entry wound on her forehead and pulled her onto his lap and held her upright so she wouldn't choke on her own blood.
Hernandez also instructed a bystander how to apply pressure to the wounds of Ron Barber, Giffords' district director.
Barber told Hernandez, "Make sure you stay with Gabby. Make sure you help Gabby," the Arizona Republic reported.
Hernandez then used meat smocks from Safeway to apply pressure to the entrance wound - unaware there was also an exit wound. He said she was conscious, but quiet.
Hernandez stayed with Giffords until the paramedics arrived. He rode with her to the hospital squeezing her hand, and he said she squeezed his back.
State Rep. Matt Heinz, D-Tucson, and a hospital physician told the Arizona Republic that the fact Hernandez was nearby probably saved her life.
Outside the hospital just before midnight Saturday, in an exchange witnessed by POLITICO, Tuscon Mayor Bob Walkup briefed a group of about a dozen locals who had gathered around a make-shift vigil and pointed to Hernandez as the "young man" likely responsible for saving Giffords' life.
"Of course you are afraid, you just kind of have to do what you can," Hernandez, 20, told the Arizona Republic. "You just have to be calm and collected. You do no good to anyone if you have a breakdown … It was probably not the best idea to run toward the gunshots, but people needed help."