Authorities said they are close to bringing criminal charges against staff at a northern Minnesota senior home where residents were allegedly beaten, sexually assaulted and denied vital medical care.

The assisted-living facility, Chappy's Golden Shores in Hill City, had its state license revoked in February following a far-reaching investigation by the Minnesota Department of Health. Since last fall, the agency has released a dozen separate reports alleging serious harm, including physical and sexual abuse, of residents at the now-shuttered facility.

Taken together, the state investigative reports span hundreds of pages and paint a disturbing portrait of conditions at a remote facility that once housed nearly 40 vulnerable residents, including people with mental and physical disabilities. In one case, a man was beaten so severely that blood poured from his head and he later died of brain injuries, the state alleged. The cases are so alarming that senior advocates have repeatedly cited them as part of a broader push for tighter regulation of assisted-living facilities, which are now unlicensed in Minnesota.

The allegations have also attracted the attention of local law enforcement officials and prosecutors. On Wednesday, Aitkin County Sheriff Dan Guida said he knows of at least five criminal investigations — "all significant in scope" — that could lead to felony and gross misdemeanor charges. He said several search warrants have already been executed.

"People will be held accountable," said Guida, who declined to specify the nature of the charges and when they would be filed. "There has been a substantial amount of evidence gathered, and no one is taking this lightly."

Late on Tuesday, the state Department of Health released still more documents detailing alleged maltreatment. One former male resident told state investigators that he was sexually assaulted by a staff member while receiving assistance in the shower. He also described several incidents of physical abuse by female staff members, which caused him to fall and suffer recurring headaches, according to a state investigation concluded last month.

In another report, state investigators found that management of Chappy's violated state law by allowing residents to move back into the facility while its home care license was suspended. The facility then failed to provide appropriate care and supervision of the residents, all of whom had medical needs. One of the residents who moved back to Chappy's had congestive heart failure, kidney disease and diabetes; the resident's condition quickly worsened and he had to be hospitalized. Investigators who visited the building found it in disarray, with medical supplies spread about and mold growing in urinals.

The state also documented incidents of financial exploitation.

The new allegations follow a state report issued in January that described a brutal beating and death of a vulnerable resident. In that case, a 58-year-old man with dementia, Steven G. Nelson, died from brain injuries after he was repeatedly punched in the face by one staff member while another employee held him down and a third watched and did not report it, according to a state investigation. Nelson was "bleeding from his head and face" and suffered an internal brain hemorrhage, the state report said. Nelson later died, apparently of brain injuries.

The assisted-living industry has mushroomed in recent years, admitting sicker residents with a wider range of disabilities. Yet Minnesota's consumer protections have not kept pace with these changes, advocates say, exposing residents to serious harm and premature deaths. Minnesota is the only state that does not license assisted-living facilities.

"It is shameful that a facility like Chappy's was allowed to operate for so long," said Kristine Sundberg, president of Elder Voice Family Advocates, a grassroots group of relatives of abuse victims that has been documenting incidents of maltreatment. "If ever there was a case that points to the need for assisted-living licensure, this would be it."

Jason Steck, an attorney in Edina representing Chappy's, said many of the reports alleging maltreatment against Chappy's and its staff lack key facts and are "too vague to corroborate." For instance, he said, the state report that documents the sexual assault in the shower does not identify the perpetrator, the accuser or when it occurred.

Investigators also failed to interview Chappy's owner, Theresa Olson, before releasing their findings, Steck said. And he said the report alleging the beating death was based on false statements made by a disgruntled employee and her daughter.

"We are left in the position of trying to respond to ghosts," Steck said.

Connie Billmeier, Nelson's older sister, said the report concerning her brother was detailed enough that she and her siblings have filed legal action against Chappy's.

She said she is still haunted by traumatic memories of visiting her brother last September at a Duluth hospital after he was hospitalized with an unexplained brain injury. Billmeier recalls her once-gregarious brother staring blankly into space. He spent the final weeks of his life drifting in and out of sleep, she said, unable to recognize family members.

"I am sickened by it all, just sickened," Billmeier said of the latest allegations. "These people are not just making this stuff up."