MINNEAPOLIS (AP) — Andrew Engeldinger’s parents were worried about their son’s growing paranoia. In 2010, they sought help, enrolling in a 12-week class for families of the mentally ill.

For the last 21 months, the family said they reached out in hopes he would seek treatment. It was to no avail, as Engeldinger spurned their attempts at contact.

On Thursday night, they learned he was the gunman in Minnesota’s deadliest workplace shooting.

“It’s not unusual when you’re isolating yourself, which we know that he did, that eventually the only people you have left is your family and your co-workers, and often your paranoia translates to them,” Sue Abderholden, a mental health organization executive who is serving as spokeswoman for Engeldinger’s family, said Saturday.

Police say the 36-year-old Engeldinger shot and killed Reuven Rahamim, the founder of Accent Signage Systems; employees Ronald Edberg, Rami Cooks and Jacob Beneke; and Keith Basinski, a UPS driver who made a delivery at the wrong time. Two other employees remained hospitalized, one in critical condition and the other in serious condition.

The officers who responded to what Police Chief Tim Dolan called a “hellish scene” eventually found Engeldinger’s body in the basement. Officers who searched his south Minneapolis home later Thursday found another gun and packaging for 10,000 rounds of ammunition.

Police and company representatives have not yet said why Engeldinger was fired from a job he had held since the late 1990s.

Jim Dow, a sales representative who frequently visited the business, said Saturday that he’d spoken to Accent employees and family members of victims. He said they told him that in recent months, Engeldinger had been running afoul of managers with confrontational behavior and unexplained absences from work.

“He was getting mouthy, belligerent,” Dow said. Cooks, who’s been described as Rahamim’s right-hand man, “would take him aside and tell him that’s not acceptable,” Dow said. “He’d straighten up for a while and then this would crop up again.”

Dolan said it was clear that Engeldinger targeted some victims while bypassing others. Many of those killed or injured were management.

Engeldinger wasn’t always a problematic employee.

Barry Lawrence, an ex-employee, trained Engeldinger on a sign engraving machine and recalled that he was “sharp, intelligent.” He said though Engeldinger mostly kept to himself, he’d occasionally join his co-workers for drinks after work.

But, upon hearing of the shooting, Lawrence said he had a gut reaction.

“To tell you the truth, my first thought was Andy,” said Lawrence, who left Accent in 2003. “He was pleasant enough to work around, but he just seemed a little off all the time. You get a feeling about people, nothing you can put your finger on.”

Abderholden, the executive director of Minnesota’s chapter of the National Alliance on Mental Illness, said she didn’t know when Engeldinger’s family first became worried that he had a mental illness. Two years ago, Chuck and Carolyn Engeldinger — who raised Andy and his two siblings in the Minneapolis suburb of Richfield — enrolled in NAMI’s free, 12-week “Family to Family” course.

The classes, offered nationwide and taught by people who have had loved ones suffer from mental illness, include scientific and medical information about causes and symptoms, as well as concrete steps for trying to deal with the sufferer. They also have guidance for family members to cope.

“Sometimes it doesn’t work, but you still are at least armed with the information to help you know what to do,” Abderholden said.

Andrew Engeldinger never sought treatment to his family’s knowledge, Abderholden said, and was never diagnosed with a specific illness. It wasn’t long after his parents took the class that he cut off contact with the family, although Abderholden said she didn’t know if pressure to seek help led to the estrangement.

Brian Jorgensen, who lived next door, said they only occasionally acknowledged each other when both were cutting the grass or shoveling sidewalks. He said Engeldinger wore sunglasses all the time.

Engeldinger was “just a quiet person who kept to himself but did not engage with us. And we didn’t engage with him either because it just felt like he didn’t want that kind of contact.”

Outside of Accent Signage on Saturday, some residents of the Bryn Mawr neighborhood laid flowers at a memorial. Another swept up leaves in front.

A father-son duo of UPS employees, Dan and Nathaniel Miller, walked around the building and prayed. Basinski’s death “hit me really hard,” Dan Miller told the Star Tribune.

Abderholden said the likelihood of violence by a mentally ill person is very low, and that Engeldinger’s family wouldn’t have had reason to suspect he was capable of such violent acts. She called the family “extremely close” and said they are distraught.

“They just have deep sorrow about what happened, and if there was any way they could bring those lives back they would,” Abderholden said. “They don’t want to detract from the focus on those lives.”

• Associated Press