The Eden Prairie man who drowned his infant son in a laundry tub nearly two years ago is mentally ill but not dangerous, a judge declared Wednesday, clearing the way for his eventual return to society.

In a detailed decision that acknowledges the uniqueness of the case, District Judge Jay Quam found Randel Richardson, 38, is not a threat as long as he continues to take medication that treats his major depression and prevents serious psychotic episodes like the one that caused him to drown his 6-month-old son, Rowan.

However, his condition requires that he be committed as a mentally ill person for six months. Then he will be re-evaluated to determine whether he is eligible for release or goes to a transitional program before he returns to his family.

Richardson's dedication to maintaining his mental health, Quam wrote, "will be forever reinforced by the shame and guilt" of what happened to his son.

"The knowledge that his failure to take medication led to Rowan's death will be a powerful motivator that will keep Mr. Richardson medication compliant for the rest of his life," he wrote in the 33-page order, which noted Richardson did not have a history of violence or mental illness before the episode that triggered the drowning.

Quam's ruling denied the Hennepin County attorney's request that Richardson be declared mentally ill and dangerous and remain committed indefinitely at the Minnesota Security Hospital in St. Peter.

The county's attorneys are deciding whether to appeal.

"We're concerned that if he is not under close surveillance that there is a risk for public safety," Assistant County Attorney Carla Hagen said.

Both the circumstances and outcome of the case were extraordinary. Of about a dozen cases tried last year to determine whether people were mentally ill and dangerous, the county attorney's office only lost one.

Richardson was cleared of first-degree murder by reason of mental illness last April.

His attorney, Chris Petros, said Wednesday that it's uncertain when Richardson will be transferred from St. Peter, where he is currently held.

It depends on available beds in area mental health facilities, as well as whether the county attorney's office decides to appeal.

Accepted or pariah?

In his order, Quam also said that should Richardson's symptoms return, they would do so slowly, yet visibly, allowing for quick intervention. If they do return, he wrote, it's more likely Richardson would be suicidal than homicidal.

"As morbid as it is, this makes a difference," he wrote, referring to the statute determining whether Richardson is a danger to others.

Still, Quam noted, Richardson's support system, including family, friends and church, could be on shaky ground.

"No one can know at this point whether Mr. Richardson will be accepted by his friends and family as a victim of his unexpected mental illness, or whether he will be ostracized as a pariah," Quam wrote.

Quam's order follows the civil commitment trial last month in which Richardson testified he is not dangerous and is willing to undergo intensive treatment upon release. A psychiatrist testified on behalf of Richardson that he is competent for release, while two psychologists appointed by the court and the state testified Richardson is still dangerous.

Both he and his wife of 17 years, Kari Richardson, testified in detail about Richardson's depression, first believed to be a stress-related funk, that placed him on short-term disability from his job as a Cargill supply-chain analyst in May 2010.

He visited several doctors, was briefly hospitalized and was given medications, which he at first resisted taking and later stopped taking with a doctor's approval because of the side effects.

When he drowned his son on July 31, 2010, Richardson suffered the delusion that he could no longer provide for his family and believed he was sparing his son further misery by drowning him.

At the time, Kari was grocery shopping in preparation for the arrival of the couple's two older children, who were staying in Memphis with their grandparents.

Kari Richardson declined to comment at length Wednesday but said she was processing the outcome and telling friends and family.

Petros said both were happy but aware of the challenges Richardson faces between the stigma of mental illness and what he did to his son, as well as reintegrating with his family.

"He will have a lot of stress on him," Petros said. "Is he more well-equipped to face that stress? Definitely."

Abby Simons • 612-673-4921