(CNN) Brent Doonan saw the bright muzzle flash of the Colt .45-caliber revolver and crashed facedown to the floor. He watched as his blood spread in a widening pool on his office carpet.
"My God this is real," he thought as the vacant-eyed shooter wheeled away from him and started firing at others in the office complex. "The son of a b****h just shot me."
Doonan was the co-owner of an Atlanta day trading firm in 1999 when one of his customers strolled into his office displaying a strange grin. The man, Mark Barton, then pulled out two pistols from his waistband before methodically shooting Doonan and others while bellowing, "I hope this doesn't ruin your trading day."
Barton would later commit suicide, but not before he shot and killed nine people and injured 13 more to become one of the nation's most notorious mass murderers.
"I thought he was my friend," Doonan says. "One second he's smiling, and the next second his face goes blank and you're on the floor after being shot."
Surviving with the guilt of living
Doonan is a member of a grim fraternity of people who narrowly missed death at the hands of a mass killer. Their ranks grew last week when James Holmes was accused of killing 12 people and wounding 58 others in a movie theater.
Though media attention has focused on the resilience of the survivors in the immediate wake of the Aurora, Colorado, shooting, Doonan represents a part of their story that's seldom told: What happens to them years after the television cameras and reporters have left?
That question drove Ron Franscell to track down survivors of some of the most notorious mass killings in American history. He wanted to know why some survivors find a way to move on, while others never recover.
What he discovered was disturbing. Most of the 30 survivors he tracked down for his book, "Delivered From Evil," had lost the will and ability to live, he says.
"They're already dead," Franscell says. "They're just waiting for the body to stop. They have no tools to be what they were before."
Most of the people Franscell interviewed missed death "by a hair's breadth." At least two of them talked with CNN about the Colorado shootings.
Among Franscell's survivors: an idealistic college student shot by the infamous University of Texas Tower sniper in 1966 who decided to enter the ministry; a survivor of the 1984 McDonald's massacre near San Diego who developed a fetish for firearms and serial killers; and a survivor of a 1949 rampage who buried his memories in an old suitcase no one wanted to open.
Opinion: Aurora shooting like reliving the Virginia Tech ordeal
'I don't care to know his name'
Some people may say the Colorado shooting victims need to learn how to forgive the gunman to move on.
Franscell doesn't buy that. The survivors who fared the best, he found, didn't grant pardons.
"They don't absolve their would-be killers and they haven't stopped crying, even decades later," he says.
A little anger and competitive zeal can actually help, says Doonan, whose gripping account of survival is chronicled in Franscell's book.
Doonan was shot five times. He eventually lost his body's entire supply of blood. A surgeon who got to Doonan as he lay bleeding in an office told him that if he closed his eyes he would die.
But Doonan says he was determined not to let Barton win. He was a star wrestler in high school, a competitor who was also supremely fit. Anger fueled his survival instinct.
It still does.
"At the end of the day, he's dead, I'm alive and I'm moving on," he says of Barton.
Stories of survival amidst shooting
Doonan forged a new life for himself. He left Atlanta after recovering, got married, had a son and is now vice president of Doonan Peterbilt, a heavy trucking company in Wichita, Kansas.
But old memories returned when he heard about the Colorado shootings. When he pores through the news accounts, he grows angry when he realizes the name of the alleged gunman is better known than those of the victims.
"I don't care enough to know his name," Doonan told CNN. "He's a piece of s**t to me. These guys do it, and their names are out there forever. Victims are left to sink or swim."
Franscell says Americans' reactions to mass killings are now ritualized: heroic stories about survivors, calls for gun control, psychologists offering insights into the mind of the twisted killer on television.
"We talk about 'remember the survivors,' but really can you name another person who was dead or wounded from the Tucson shooting other than Gabby Giffords?" asks Franscell, referring to the 2011 shooting of the former Arizona congresswoman that claimed the lives of six people, including a young girl, and wounded 12 others.
Doonan says one of the first notes he received after being wounded offered him the best recovery advice.
"I got one right out of the gate that said cling to your faith, family and friends and you will never lose your way," Doonan says. "That was my rock."
Doonan did other things as well. He sought out counseling, wrote about his experiences in a book, "Murder at the Office," and even reached out to the mother of the man who tried to murder him. (He says she never responded to his request to talk.)
Still, memories of the shooting welled up at unexpected moments.
Once, Barton came into his bedroom one night. It was nightmare.
"He was standing at the foot of my bed laughing, as if to say, 'I got you,' " Doonan says.
Where was God in Aurora massacre?
Shrinking the monster down to size
Sometimes those nightmares infiltrate survivors' waking hours, Franscell says.
Some never feel safe anywhere. Every public space looks like a potential graveyard. Survivors get paranoid about strangers; they sit near exits or with their backs to the walls. They second-guess routine decisions for fear that they'll run into the monster who almost took their life -- even though they know he's dead or locked away -- or perhaps another killer.
"Every choice they make, that face comes back to them and they say, do I turn left here or if I go left is that going to put me back into that? " he says. "That monster is part of every decision they make."
Some can't forget or forgive their monster so they find another solution -- they shrink their monster down to size.
"They make a certain peace with the memory of their monster," Franscell says. "They chose to limit that monster's role in their lives."
Some start to recover when they think more about those people who didn't make it. The question is inevitable: Why me, and not them?
Often they answer: I owe a debt to the dead to live more fully because I have a second chance at life and they didn't, Franscell says. One of those who took that attitude was the Rev. Roland Ehlke, who was shot during one of the most notorious mass killings in American history. A movie was made about the shooting, and it's even referred to in a scene from the Vietnam film "Full Metal Jacket."
It's the University of Texas Tower sniper shooting.
Opinion: Aurora survivors, stay strong
Ehlke was strolling on the campus of the University of Texas in Austin in 1966 during a muggy, summer day when Charles Whitman shot him from the observation deck of a tower on the campus.
Whitman, a former altar boy and Eagle Scout, was also a former U.S. Marine who, according to his father, could "plug a squirrel in the eye" by the time he was 16. He killed 16 people and wounded 31 that day. (He shot some people from as far as 500 yards.) Two police officers and a civilian eventually snuck up the tower, and shot him to death.
Ehlke was wounded three times and lost a friend. He gained, though, a new perspective. He joined the Peace Corps and then went to seminary. He collected four master's degrees and a doctorate. Today, he's a Lutheran minister.
"It sounds strange to say that it was a very enriching experience to come close so death," he says. "I realize how fragile life is and how it can be taken away so easily."
Ehlke says he can't figure out why he survived and other people didn't.
"For me, it's a mystery," he says. "We can't always answer why this one and not yet another. That's part of living by faith, knowing that we don't have all the answers."
Another survivor of the Whitman rampage wasn't so philosophical.
According to Franscell, Houston McCoy, one of the Austin police officer who killed Whitman, suffered from post-traumatic stress disorder for years.
"If I get to heaven and see Charles Whitman," he once said, "I'm going to have to kill him all over again."
Ehlke says the 1966 shootings marked a dark detour in American history. Random shootings, distrust of strangers, declining church membership -- all those became the norm.
"As a kid in the summer we'd hop on our bikes, ride four miles to the lake and go swimming all day and be told to just be home for supper," he says. "You wouldn't think of doing that today."
Warning signs of violence: What to do
The suitcase no one wanted to open
Other survivors don't recover as well as Ehlke. Like soldiers returning from war, they suffer from PTSD -- except for one telling difference.
"Soldiers are at least minimally prepared for this; these folks are not," Franscell says.
Some burrow inside of themselves. They can't connect emotionally with others, can't keep jobs or maintain a marriage. Some abuse drugs Franscell discovered.
One survivor started mimicking the mass killer who almost killed him.
In 1984, James Huberty pushed a mother and child out of the way as he entered a McDonald's near San Diego, dressed in camouflage pants and combat boots.
After yelling, "Everybody down," he shot and killed 21 people, many of them children. The images of the bodies of children, sprawled next to their bicycles outside the restaurant, are still burned in the memories of people who saw the news reports that day.
One of the survivors Franscell profiled was 12 at the time. The boy physically survived, but psychologically he disintegrated.
He developed a drinking habit and became emotionally withdrawn. He flinched at loud noises and unexpected touches, once slugging a teacher who grabbed his arms.
He became obsessed with guns as well as books and movies about serial killers. He even started dressing in the camouflage pants and tight, dark shirts that Huberty wore on that fateful day, Franscell says.
At a loss: Comforting grieving parents
And he could never step into a McDonald's again.
He eventually recovered and changed his name. But his turmoil lasted for years, as it will for many of the victims of the Colorado shootings, Franscell says.
"There are things that they don't shake, and they never will," he says. "I guarantee you that they're all having nightmares."
The story of Charlie Cohen is one of the most heartbreaking that Franscell uncovered.
Cohen was only 12 when Howard Unruh, a World War II veteran, went on a rampage and murdered Cohen's parents, Maurice and Rose, in Camden, New Jersey. Cohen's mother ordered him into the closet as Unruh's heavy footsteps thundered up their home's stairs. Cohen huddled in the closet as he heard Unruh shoot his mother to death. Unruh would eventually kill 13 people, including three children, that day in 1949.
Cohen grew up to become a linen salesman who was known for his sense of humor. Yet he never talked about his parents. When any of his three daughters asked about them, he said they died in an accident.
Yet his daughters sensed that Cohen was hiding something. He wouldn't let them purchase pets or cut flowers for the same reason -- they died. And once, when he granted a rare interview to a reporter about his parents' deaths, he said:
"I was a kid. I listened to my mother. She yelled, 'Hide, Charles, hide!' That's what I did. I hid in the closet.
"Thing is, I'm still in there."
Unruh was arrested and imprisoned in a state insane asylum. Cohen dreamed of a day when he would get a call telling him that Unruh was dead. He told Franscell that he would go to Unruh's grave and piss on it, and bury an old, brown suitcase filled with press clippings of his parent's death.
"The suitcase that he put all of the mementoes in was, in effect, everything that was inside of him," Franscell says.
Cohen never got his chance. He died of a heart attack at 72 in September 2009. Unruh outlived him by six weeks. He died at 88 in a nursing home, still lucid up to the last moments of his life, Franscell says.
When Cohen's family found the suitcase, Franscell says they called him to ask if he wanted it.
"Nobody had ever opened it, although it was known that it had existed," he says.
Cohen's memories remained locked away in his suitcase. He never got a chance to bury it, nor mark Unruh's grave. Someone else did that -- though not in the way Cohen intended.
When Unruh was buried in an unmarked grave, a cemetery worker planted an object in the fresh dirt. It was an American flag to honor Unruh's service in World War II.