A mental health patient who was pepper-sprayed by a corrections officer at the state-run Riverview Psychiatric Center intends to sue the state for $1 million, her attorneys said.

The potential lawsuit is based in part on a state investigation in March that concluded staff at Riverview abused Arlene Edson when she was pepper-sprayed and held in restraints for several hours on Dec. 2 while she was naked, alone in her room and not threatening employees.

A notice of claim, the first step in what could turn into a lawsuit against the state, was mailed Tuesday to potential defendants, including Riverview Psychiatric Center in Augusta, former nurse William G. Lord, Gov. Paul LePage, the Maine Department of Health and Human Services and numerous other state officials. Lord, 39, of Wayne, was fired over the incident, according to court records, and more recently was charged with aggravated assault for throwing his 3-month-old child down a flight of stairs, police said.

“I’m a sucker for a challenging case, and this is a challenging case. We’re David, and they’re Goliath,” Daniel Lilley of Portland, Edson’s attorney, said of the lawsuit he expects to file within the next few months. Maine gives state agencies and employees immunity from lawsuits in many situations, but what happened was so harmful to Edson that she should be able to overcome those hurdles and go before a jury, Lilley said.

In many cases, Maine law requires people to get the Legislature’s approval before suing, limiting legal actions against the state.

Rep. Richard Farnsworth, D-Portland, chair of the Legislature’s health and human services committee, said state laws are stacked against potential litigants, but suing is possible in unusual and especially egregious circumstances.

“They have to meet a very special set of criteria, and it’s not easy to do,” Farnsworth said.

Andrew Mason, an attorney who works with Lilley, said because Riverview employees overstepped their bounds by going beyond what would be their normal duties working for a state mental hospital, Edson does not need the Legislature’s approval before filing a lawsuit.

Riverview Superintendent Jay Harper, who was hired in March and was not the superintendent when Edson was abused, declined to comment on the potential lawsuit.

“I’m looking forward to reading it and seeing what they have to say,” Harper said.

Edson remains at Riverview and couldn’t be reached for this story, but the 30-year-old from Fryeburg has previously told the Press Herald that she has been held in restraints against her will on several occasions, she doesn’t trust the staff, and she doesn’t believe she’s being treated for her illness. Edson said she’s been at Riverview since 2011 because she was found not criminally responsible for arson and assault. She has said she suffers from post-traumatic stress disorder and depression.

Mason said Edson called them “out of the blue” a few weeks after the Maine Sunday Telegram printed an investigative report about Edson’s case and what former employees described as a culture of dysfunction at Riverview, where lower-level employees routinely abused patients by withholding food, tackling them or placing them in seclusion.

“You get fired up about cases like this,” Mason said. “This poor woman went through so much, and she needs someone to stand up for her.”

Until notified by the Press Herald in September, Edson was unaware that the state Department of Licensing and Regulatory Services had completed a report in March that criticized Riverview employees for abusing her. The report also found that employees downplayed what happened to make the incident seem less severe, and for months failed to report the abuse, as required by law. Numerous Riverview employees knew about the December incident, but it wasn’t reported until a nurse insisted in February that the case be turned over to state authorities, the report said.

Lilley said he is taking the case on a contingency basis, hoping it could not only help Edson, but also force changes in how patients are treated at Riverview.

“Once you hit them in the pocketbook, things tend to change,” Lilley said. He said the case could turn into a class-action lawsuit by including others who were abused at Riverview.

The hospital frequently puts patients into seclusion, compared with national averages at state hospitals, but the use of seclusion has decreased over the past several months.

Harper has said the pepper-spray incident “should not have happened.” He is working on a number of reforms to improve the hospital, including employing techniques to defuse confrontations with patients and limit the use of seclusion.

“We have implemented the reforms, and it’s been going great,” Harper said during a brief interview Tuesday.

Riverview lost its federal certification with the U.S. Centers for Medicare and Medicaid Services in September 2013, and with it, $20 million in funding. Riverview is seeking to be re-certified, but failed in its first attempt this summer to regain good standing.

When asked whether the lawsuit could result in Edson leaving Riverview to be treated somewhere else, Lilley said that “it’s not something that we’ve thought of yet,” but it could be a desired outcome.

“That’s a tall order,” Lilley said, “because people are sent to these places and it’s very difficult to get them out, especially if they have been sent there by the criminal court system.”