A resident at an assisted-living facility in Bloomington died of acute morphine toxicity in January after being given two large overdoses of the drug, the Minnesota Department of Health said Tuesday.

Investigators have blamed the nurse who administered the narcotic, who thus far has not cooperated with the inquiry.

Bloomington police have referred the case to the Hennepin County attorney’s office for consideration of charges against the nurse, according to Deputy Police Chief Vic Poyer. “We have to prove it’s a crime and not just a mistake,” he added. “The case isn’t closed.”

The woman, a resident of Nervana’s Caring Hands, received two doses of morphine that were 20 times the prescribed amount during the night on Jan. 15, according to Health Department investigators. “The client was sedated by the medication overdose and did not regain consciousness” and died the next afternoon, the report said.

Relatives of the woman told a state investigator that they questioned the nurse about the need for the narcotic, pointing out that she did not seem to be in pain, but acknowledged she was having trouble breathing.

The Health Department did not release the name of the resident or the nurse. The home’s operator, Nervana Ramnarain Ramdyal, did not return a call for comment Tuesday.

According to the report, the woman had been living at the home for about two years, when she was hospitalized for pneumonia for a week, and then returned to the home. On the night of Jan. 15, the nurse gave the woman morphine, which was to be administered to address her pain and shortness of breath, but “an error was made when calculating the dosage.” The resident died the next day.

The home’s owner said she didn’t provide any training to the nurse, noting that the nurse had graduated within the previous year and had recent training.