Daniel Hernandez had only been on job five days, but when the intern for Democratic Rep. Gabrielle Giffords heard someone yell "gun!" on Saturday in the midst of a deadly shooting spree in Tucson, Arizona, he sprang into action and may have helped save his boss' life.

Giffords was shot point-blank in the head by a disturbed man, Jared L. Loughner, who is in police custody and has been charged with five federal counts, including the attempted assassination of a member of Congress. In total, 20 people were injured and six killed in the spree, but authorities are crediting Hernandez, 20, for possibly saving the congresswoman's life.

Hernandez, who trained as a certified nursing assistant and knows basic life-saving techniques, told CNN that he rushed to Giffords' side and used his bare hands to apply pressure to the wounds on her head to stop the bleeding. He also lifted her head to make it easier for the wounded politician to breathe after he realized she had been a victim in the incident. "She was alert and conscious, but she wasn't able to speak, so the way she was communicating was by grabbing my hand and squeezing," Hernandez explained.

As the shots rang out, Hernandez said he was helping to manage the flow of people waiting to speak to the congresswoman at one of her "Congress on Your Corner" events, where she would talk to constituents one-on-one. He was 30 feet away when he heard the first shots and, assuming that Giffords would be a target if there was a gunman, he said he ran toward her in order to help out in case anyone was injured.

When he arrived at her location, he saw several people on the ground and tried to help two or three who still had pulses and were breathing before he noticed that Giffords had been hit and went to her side. Seeing that she was shot in the head, he told CNN, "She then became my first and only priority."

Thanks to the nursing program he completed in high school and training in phlebotomy (blood drawing), Hernandez said he was able to use his basic first-aid skills on Giffords, making sure she was breathing properly and then applying pressure to her wounds.

"I don't know if the gunshots were still going on when I was running toward the congresswoman," said Hernandez when asked if he was ever concerned that he might also be injured if the gunman was still actively shooting. "My only concern was trying to help those that needed the help. After I got there and I saw that the congresswoman had been injured, I saw that she was injured pretty badly and I wanted to make her my first and only priority." Employees from a nearby supermarket brought out clean smocks from the meat department to cover Giffords' wounds until the paramedics arrived.

Hernandez said he's confident that Giffords will survive her injuries. "There was never any doubt in my mind that she would pull through," he insisted. "And she will pull through, because she's definitely a fighter."

Once the ambulance arrived, Hernandez rode in it with Giffords and, in the aftermath, he's taken a decidedly humble tone about his actions. "People have been referring to me as a hero. I don't think that I am. I think the people who are heroes are people like Gabby, who have dedicated their lives to public service," he said. "It just makes me happy to know that I could help her in any way that I could."