Chuck and Carolyn Engeldinger had their son cremated to spare their other children the sight of someone protesting at his burial or desecrating his grave.

Instead, strangers from near and far have written, saying they, too, know the terror of watching a loved one spiral into a world of delusion.

And last week, a card came in the mail from Green Bay. Signed by the siblings of UPS driver Keith Basinski, it offered the Engeldingers sympathy for the loss of their son.

Their son, Andrew Engeldinger, who pulled a pistol from his waistband Sept. 27 at the Minneapolis company where he was an engraver and fatally wounded six people before turning the muzzle on himself, in what's believed to be the deadliest workplace shooting in state history.

The Engeldingers sat down Thursday in their modest Richfield home to talk about their son's gradual degeneration from a happy childhood into a surreal funk that they believe was schizophrenia, the same progressive brain disease that struck Carolyn's late mother and another close relative.

They said they granted the interview because they want their son to serve as a powerful example of why society must find more effective ways of identifying and helping people with mental illnesses.

"We need to find some meaning in all the damage Andy inflicted," she said. "We can't undo it, but we have to try to do something for the sake of all those families and our son."

A shrinking personality

Framed by a bowl haircut, Andy Engeldinger's smiling face is sunny in old photos -- holding up a sunfish, clowning with his older brother and younger sister.

"They were the Three Musketeers," said their father, who described Andy as precocious and so smart that his nickname was "The Little Professor."

Looking at the photos now, his mother said she can see his personality "shrinking a little" as he neared high school graduation, a compact, good-looking teen who lifted weights and obsessed about his receding hairline.

He drank, smoked pot, acted hostile and laid around the house long after graduation. His parents insisted he get treatment, but they said he remained hostile after, and they refused to let him move back home. He bounced around before getting an apartment.

They now suspect schizophrenia was already causing him to self-medicate and push people away, including a girlfriend with whom he broke up because he believed she cheated on him with his best friend.

"At the time, we had no inkling of an underlying mental illness other than depression," for which he was briefly medicated until he wouldn't take the pills, Carolyn Engeldinger said.

Things looked up for a while when he got the job at Accent Signage Systems in 1999. He got regular raises and chances to learn and even improve the craft of engraving, his dad said.

"He worked really, really hard," said his mom, who added that owner Reuven Rahamim seemed to like her son and even returned from Israel with a gift of rare, exotic soap for his young employee.

Soon Andy could afford a little stucco bungalow in south Minneapolis that his dad helped him fix up. He decorated with Japanese art, kept tropical fish from Africa and grew Bonsai trees in dishes.

"He had a lot of interests," said his mom. "Until he didn't."

He even took his parents up on their offer of tuition if he went to Minneapolis Community & Technical College. An admissions worker confirmed Andy took several courses, including algebra and psychology, and got good grades. His mother said he seemed to like it but started to perceive that the other students didn't like him, so he quit.

Darkness falls

His parents said his delusions and paranoia grew gradually, making it hard for them at first to accept that he was mentally ill.

In the early 2000s he began to claim that bosses mistreated him. He filed a discrimination complaint with state human rights officials, but it didn't go anywhere. By the fall of 2010, some of the things he told his parents disturbed them so much that they'd leave the room.

He perceived people as talking about him, pointing at him while he roller-bladed, their lips moving.

"When he came over, he'd be on his tip-toes, nervously looking out the window," his dad said. "When we took family pictures, he'd be sitting apart and silent."

He repeatedly tried to convince his parents that the government was surveilling and photographing him because it knew he had special abilities. Finally his parents told him they wouldn't listen to any more delusions and demanded he see a doctor. That's when he cut his family off.

"He was against seeing doctors or talking to anybody about his mental health," his dad said.

He ignored their holiday invitations. A $1,000 check they sent him went uncashed. They stealthily drove by his house to try to get a glimpse of him and were relieved to see he was keeping the grass cut.

"Once I went to his house and tried to talk to him through the door, but he wouldn't respond," Chuck said.

"We tried so hard to get him help," his mother said. "But he was an adult, and he was functioning well enough to have a house and a job and pay taxes. We couldn't force him. But he was suffering terribly."

Feeling helpless, the couple enrolled in a course offered by the National Alliance on Mental Illness, sharing stories with other families and learning some of the science behind schizophrenia. They've kept a big binder with the course materials, including copies of X-rays of brains ravaged by the disease, which appears to leave holes where normal brain tissue should be.

"You feel guilty because you realize he probably got it through your genes," Carolyn said.

He shot alone

Andy's parents lived in fear that he would kill himself or get fired and become homeless. It's unknown whether he too feared those things or prepared specifically for them; police have yet to reveal the contents of his computers or personal records.

What is known is that he bought two Glock semiautomatic handguns, stockpiled ammunition and practiced about an hour almost every Sunday at the Burnsville Pistol Range.

"Engeldinger always came alone, and [he] never talked to any of the other customers or staff," Roger Hird, owner of the pistol range, told police, according to a report.

His parents said they had no idea that Andy was training with a handgun. When police recently revealed they found packaging for 12,000 rounds of 9mm cartridges in his basement, "it blew us away," his father said. "He'd never been interested in that stuff."

Though clueless about that, Andy's parents worried that his weakening grip on reality would affect his job, and they were right. After the melee, police documented that bosses had warned him about tardiness, outbursts and other issues. Police also found prescription bottles for depression and insomnia but not, apparently, anti-psychotics.

"The standards at Accent were really high," said Meaghan Norlander, comptroller there for two years ending in 2008. "Andy was quite an introverted, sensitive person. He really wanted to do a good job. He just didn't seem to be able to please [Rahamim]."

She recalled the two shouting at each other in 2007, something she said wasn't unusual for Rahamim. Meanwhile, she said, Andy "internalized everything," such as when he took bitter offense at her mispronouncing his name.

"He just seemed to be a tortured soul," Norlander said.

Engeldinger began taking his lunches alone, in his car, employees told police.

Finally, company officials decided his chances were up, and they chose the afternoon of Sept. 27 as the time to break the news to him. When they did, he said, "Oh really," pulled his pistol and started shooting, systematically killing some bosses and co-workers while sparing others.

He then went to the basement, sat in a chair, put the gun to his head and fired. He was 36.

His parents tried to donate Andy's brain to Harvard University's brain tissue bank for mental illness research, but it hadn't been removed quickly enough.

They said if people want to help, they can support the National Alliance on Mental Illness-Minnesota or Survivor Resources, which aids victims of violence and accidents.

They also asked that people support research into brain diseases and public education on mental illness.

"Gabby Giffords. Columbine. There are too many examples," Carolyn said. "I feared suicide, but I never, never imagined these murders. That was not our child. It was a stranger."

Staff writer Randy Furst contributed to this report. Larry Oakes • 612-673-1751