AURORA, Colo. — Movie screen superheroes never die. But there were superheroes present in a darkened movie theater at Aurora Mall, and some of them did die, like Matthew Robert McQuinn, who threw his body in front of his longtime girlfriend, Samantha Yowler, shielding her from the bullets that took his life.


Mr. McQuinn, 27, was one of 12 people who were killed when a gunman opened fire in the theater early Friday, and like many of the other victims, he was young enough to have limitless possibilities ahead of him.


He and Ms. Yowler went to see the midnight premiere of the latest installment in the Batman series with her brother, Nick Yowler. He, too, leapt to protect his sister. He pulled her from the theater to safety, escaping uninjured. Jonathan Blunk, 26, a military veteran, died when he saved his girlfriend, Jansen Young.


Veronica Moser went to the movie with her mother. She was 6, too young to know much about Batman, too inexperienced to know that in the ferocious uncertainty of life, a movie theater could, without warning, become one of the most dangerous places on earth.


Veronica died on the operating table after being wounded during the shooting, her 15-year-old cousin, Katherine Young, said on Saturday.


“She was just a radiant, happy little girl,” Katherine said. “She was just so happy. She could brighten anyone’s day.”


Katherine said that Veronica, who lived in Denver, had just started swimming and had fallen in love with it.


“She was really good at it,” Katherine said. “I taught her to long-board, so she loved doing that too.”


Veronica’s mother, Ashley Moser, was also seriously injured. She was shot twice in the abdomen and once in the neck and remained in the hospital, Katherine said. “They were just over for dinner on Tuesday,” she added quietly.


Just after midnight on Friday, the gunman, armed with a small arsenal of weapons, opened fire in the theater, leaving an additional 58 people injured.


By Saturday, officials had identified the 12 who died — 10 at the scene and 2 others later at hospitals.


The Aurora Mall theater, much like movie palaces everywhere, is a deeply American place where the bonds of popcorn and a refuge from daily cares unite people from all backgrounds.


Mr. McQuinn and Ms. Yowler worked at Target, having moved to Colorado from Ohio to get a fresh start. On Friday morning, Ms. Yowler was shot in the knee, but is recovering in the hospital, said a lawyer who is acting as a spokesman for the families.


Mr. Blunk served in the Navy aboard the Nimitz and had always wanted to die a hero, his wife, Chantel Blunk, from whom he was separated, told NBC News. Jansen Young, whose life he saved, said that is exactly what happened.


“Jon just took a bullet for me,” she said on the “Today” show. Mr. Blunk moved to Colorado after leaving the service and worked here installing hardwood flooring, his father, Randall Blunk, said on Saturday. He had a 4-year-old daughter and a 2-year-old son.


Alex Sullivan was a huge comic book fan who was at the premiere to celebrate his 27th birthday. “Oh man one hour till the movie and its going to be the best BIRTHDAY ever,” he wrote on Twitter shortly before he died.


Alexander Boik, 18, known as A.J., was recalled by a friend, Jakob Bolger, as “a very heartwarming, good-minded person.”


“He’s hilarious,” said Mr. Bolger, who added that he had been friends with Mr. Boik since the two played baseball together in seventh grade.


The first victim to be identified, Jessica Ghawi, 24, had narrowly escaped a mass shooting at Eaton Center Mall in Toronto. An aspiring sports broadcaster, she had written that the experience had convinced her that each moment was precious.


In this city of 325,000, where the military has had a strong presence for almost a century, the Dark Knight sequel also drew in men schooled in combat but hoping for a few hours, to forget about the business of war. Petty Officer Third Class John Larimer, 27, a Navy cryptologic technician stationed in Aurora since October, died of injuries sustained in the shooting. Staff Sgt. Jesse Childress, 29, from Thornton, Colo., was an Air Force reservist on active duty with the 310th Forces Support Squadron at Buckley Air Force Base, according to Air Force officials.


Rebecca Wingo, 32, was a single mother with two daughters, a “lovely young woman,” her friend Gail Riffle said, who took classes at Aurora Community College and attended Mile Hi Church in Lakewood, Colo. Micayla Medek, 23, worked at a Subway sandwich shop and was trying to figure out what to do with her life, her aunt, Jennifer Zakovich, said Saturday.


Those who did not know the victims or their families mourned them as well. On Friday night, candles appeared across the street from the mall, a sign reading: “7/20 — Gone Not Forgotten.”


Many who stood around the makeshift memorial said they had come because it could have been them, or their brothers or sisters or aunts or mothers, lying bloodied on the ground. They struggled for words — “shocking,” “horrible,” “unthinkable” — that were ultimately inadequate, their voices faltering with the weight of the events.


And the victims’ families, now also bonded in their loss, recalled them with a mixture of love and the numbness of disbelief.


Ms. Medek, her aunt said, “was her dad’s best friend. She and her sister were inseparable.”


Petty Officer Larimer’s father, Scott Larimer, said his son John grew up as one of five children in Crystal Lake, Ill.


“We’re still in shock,” Mr. Larimer said on Saturday. “Unfortunately, in the military you expect him to be in harm’s way, but not in a theater.”