MINNEAPOLIS (AP) -- Andrew Engeldinger's parents pushed him for two years to seek treatment for what they suspected was mental illness, but even though he became increasingly paranoid and experienced delusions, there was nothing more they could do.

Minnesota law doesn't allow people to be forced into treatment without proof that they are a threat to themselves or others. Engeldinger's parents were horrified last week, when their 36-year-old son went on a workplace shooting spree that led to the deaths of a Minneapolis sign company's owner, several of his employees and a UPS driver. Engeldinger then killed himself.

"They wanted him to get treatment. They wanted him to get help," said Sue Abderholden, the executive director of the Minnesota chapter of the National Alliance on Mental Illness, who has acted as a family spokeswoman.

She added: "You're not going to convince someone they're ill if they don't want to believe it."

This is a problem faced by many friends and relatives of people suffering from mental illness, along with the police officers and health care providers to whom they turn for help. While a small number of people with mental illness commit acts of violence, the difficulty of securing treatment and ensuring it is successful -- and the catastrophic consequences of failure -- are common threads that often link such outbursts.

"These are not random acts of violence," said Dr. E. Fuller Torrey, a psychiatrist at the nonprofit Stanley Medical Research Institute in Maryland. "It is my personal belief that these episodes will increase in number and severity and will continue until we figure out what to do about it."

Engeldinger was never formally diagnosed with a mental illness, but his family was concerned enough by their son's behavior, which included claims that he was being followed, to enroll in a free, 12-week course for loved ones of people with mental illness before he cut off contact in late 2010.

His willful estrangement kept his parents from the basement of his small bungalow, where police said he stockpiled 10,000 rounds of ammunition and a second gun on top of the 9mm Glock semi-automatic pistol he used in Thursday's shooting. Without evidence that he was a threat to himself or others, they were unable to force him into treatment under Minnesota law.

A successful patients' rights movement in the 1970s made it difficult -- and illegal in some states -- to force a person into treatment unless he or she was homicidal or suicidal. Dr. Darold Treffert, a Wisconsin psychiatrist, coined the phrase "dying with their rights on" in 1974, after collecting stories of people who didn't qualify for involuntary commitment and later killed themselves.

In the years since, 41 states have added "need for treatment" standards to their laws that allow more individuals to be placed into court-ordered treatment programs. Minnesota is not among them.

"The pendulum is slowly returning to a reasonable balance," Treffert said. "I have comforted myself on this long mission with the realization that some things can be learned and can't be taught. We do seem to be learning slowly from tragedies."

A sly suggestion from a police officer led Kevin Earley's father to lie and say the young man was violent so that he would get treatment. Earley, then 23, was arrested after breaking into someone else's house to take a bubble bath.

"He said, 'Unless you tell them your son threatened to kill you, they won't admit him and we'll take him to jail, and you don't want that,'" said Pete Earley, an author in Fairfax, Va., who has written about his son's experience in the mental health care system.

Kevin Earley was seeing secret messages all around him, but his father never heard his clearly psychotic son threaten himself or others.

"I went in and I lied. And that got him into the hospital," Pete Earley said.

But just getting patients diagnosed or enrolled in treatment often isn't enough. Virginia Tech gunman Seung-Hui Cho was ordered into outpatient treatment before he killed 32 people in 2007.

This summer, prosecutors say, James Holmes killed 12 people at a midnight premiere of a new Batman movie in Colorado. His attorneys say he had an undisclosed mental illness, and his psychiatrist tried to report him to a campus behavioral and security committee.

Experts say it can take years before patients agree to stick with a prescribed treatment. Elyn Saks, a law professor at the University of Southern California, has schizophrenia and, without medication, starts to believe she can kill hundreds of thousands of people with her thoughts. Until the mid-1990s, when she was in her 40s, Saks tried periodically to skip her drugs.

"I felt so ashamed," said Saks, a MacArthur Foundation "genius grant" winner for her contributions to mental health law. "It's an internalized stigma. I wanted to be whole, I wanted to be well. Each time I tried to get off medication, I did it with great gusto and failed miserably." Now, she takes her pills. "Frankly, I'm sorry I wasn't smarter sooner."

Earley initially didn't stick with treatment after his father lied to get him into a hospital. He became violent -- he was shot with a Taser by a police officer at one point -- and was hospitalized five times before he realized he couldn't live without his medication.

"I know I have a mental illness and if I leave it untreated it will destroy me," said Earley, who now works full time as a peer counselor in Fairfax County, Va., helping others with severe mental illnesses. With treatment, he said, "I have my own apartment, a car ... I'm able to do things with friends and family. I have a job I can go to that gives me pride."

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