A male caregiver at an assisted- living facility in northern Minnesota has admitted to sexually assaulting a 78-year-old woman with Alzheimer’s disease, while the facility still faces accusations that it hid the violent incident from the victim’s family members.

In a Crow Wing County District Court hearing in Brainerd, David E. DeLong, 60, of Pine River, pleaded guilty to one count of fourth-degree criminal sexual conduct, after a staff member at Minnesota Heritage House of Pequot Lakes reported catching him in the act of sexually assaulting the woman in May 2016.

The resident, who is now deceased, was in the late stages of Alzheimer’s disease and could get around only in a wheelchair.

According to police reports, a staff member at Heritage House opened the door to the woman’s room to discover her partly naked and lying in a fetal position, with her nightgown pulled up above her waist. Just a few feet from her bed was DeLong, who was breathing heavily and was “jumping up and down” as he tried to pull up his pants and underwear, according to a police report. DeLong later provided a DNA sample that matched the semen found on the assault victim.

While relieved by the guilty plea, family members of the victim said they remain bitter about the way the facility’s staff members responded to the assault.

While staff members were preparing the victim for transport to the hospital for a sexual-assault examination, it was discovered that she had been changed into a different nightgown from the one she was wearing during the assault. The woman’s nightgown and mattress pad were placed in the washing machine, destroying possible evidence, police found.

In addition, instead of calling police immediately after the assault, the facility pulled DeLong into a conference call with staff members and then sent him home.

“There is so much about this case that is just plain wrong,” said Janine LePage, assistant Crow Wing County attorney. “The crime scene had been changed. [DeLong] was left alone in the victim’s room after [the assault]. Clearly, there was a need for training that did not happen.”

At the court hearing in Brainerd last week, several members of the victim’s family were visibly distraught — in large part because they had only just learned of the assault.

Robert Krause, 60, of Pequot Lakes, the victim’s son, said the family had been told of the assault just a week before DeLong’s plea hearing — more than a year after the incident. No one at the facility even mentioned the incident, Krause said, during his many visits to see his mother before her death last September.

Krause said he never would have allowed his mother to return to the Pequot Lakes facility had he known about the assault. Like other family members, he wonders if her rapid physical and emotional decline last summer was related to possible trauma she suffered from the incident.

“I’m her only child,” Krause said, tearing up as he spoke. “She was all I had. She was my mother. And they hid this from me on purpose. They kept a secret they had no right to keep — morally or ethically.”

Kathy Birchem, owner of Heritage House, which has 50 beds, said that the worker who reported the assault to local police “did the right thing” but that the incident could not have been foreseen, she said. DeLong passed his criminal background check when he was hired in early 2014, and he “appeared to be a caring person” to other workers, she said.

“We are just very thankful that it was caught and reported and is going through the judicial system, and people can feel that some justice is done,” Birchem said.

She declined to comment on why the victim’s family members were not contacted.

DeLong agreed to a prison term of three years, an upward departure from state guidelines that would have otherwise called for a two-year sentence. The higher sentence is based on aggravating factors: The woman was particularly vulnerable because of her age and condition, and because the incident occurred in her private room. DeLong also agreed to a psychosexual examination. A sentencing hearing is scheduled for mid-October in Brainerd.