AUGUSTA — A former Riverview Psychiatric Center mental health worker pleaded guilty Thursday to intentionally endangering the welfare of a patient being supervised at a group home.

Wayne F. Lewis, 65, of Augusta, originally was charged with gross sexual assault in the case after the woman, who was 50 at the time, told Riverview staff that she and Lewis had intercourse at his home on Jan. 10.

Riverview, the state’s forensic hospital, treats people with severe and persistent mental illness, including those charged with crimes and those found not criminally responsible for crimes because of mental illness.

The sexual assault charge was dismissed in exchange for the plea.

“This was a fair compromise,” said Lewis’ attorney, Walter McKee. “Wayne recognizes now that he crossed a boundary.”

Lewis was sentenced Thursday in the Capital Judicial Center to an initial 30 days in jail – which he is to begin serving Friday – with the remainder of the two-year term suspended. He also was placed on two years’ probation with conditions that prohibit him from being employed in the health care field.

Lewis, a mental health worker, had worked at Riverview for about five years and had been assigned to the unit where the woman was placed before she was permitted to move to a supervised group home.

Lewis also was banned from contact with the victim in the complaint unless that contact is approved in writing by the Riverview Assertive Community Treatment team overseeing her.

McKee said Lewis requested that provision.

“It may well be that, so long as her ACT Team approves, Wayne will be allowed to have contact with her again,” McKee said. “Wayne hopes so.”

At Lewis’ initial court hearing, Assistant Attorney General William Savage told the judge that Lewis had cooperated with the investigation.

Investigator Jeffrey Wrigley from the Attorney General’s Office, in an affidavit filed in court, said Lewis admitted having a relationship with the woman and said he met her during her furlough time while she was at the group home, that they talked on the phone, went for walks in the woods and had sexual contact at his home.

Lewis pleaded guilty to a felony-level charge of intentionally or knowingly endangering “the health, safety or mental welfare of a dependent person who was unable to perform self-care because of advanced age or physical or mental disease or defect.”