A 22-year-old woman has been jailed and charged with murder in connection with the heroin overdose suffered by a 62-year-old Hermantown woman who worked as a nurse.

Kathy Ann Davis was found dead in her home on Johnson Road on Nov. 30, 2014, by her husband, according to the criminal complaint.

Charged in St. Louis County District Court with third-degree murder is Kayla Jo Vranish of Duluth, who is accused of selling the drug to Davis.

Authorities determined that the heroin Davis ingested was laced with fentanyl, a potent narcotic used to supplement general anesthesia or treat long-term or chronic pain.

The opium-based medication is seldom used outside of hospitals because it is powerful and fast-acting. It's considered 80 times stronger than morphine, is highly addictive and can be fatal when abused.

"This is a very tragic incident which is occurring all too often in the Northland," Deputy Police Chief Shawn Padden said in a statement regarding Thursday's charges. "Our agency is very appreciative of … the proactive interest that the St. Louis County attorney's office has shown in this and similar drug cases submitted to their office for review of charging consideration."

Padden added that authorities across the country are attributing a dramatic rise in heroin overdose deaths to a new additive, fentanyl, in certain batches of heroin.

There have been roughly 122 reported drug overdoses in the Duluth area over the past year, police said, and this does not include people who admitted themselves to hospitals in the area.

Vranish was arrested Wednesday and remains jailed in lieu of $125,000 bail.

Autopsy results from the county medical examiner's office ruled that Davis died from an accidental "self-administered" overdose.

Her obituary on the funeral home's website said she earned her nursing degree from the College of St. Scholastica in Duluth and worked at St. Mary's Hospital, also in Duluth. State records show that her license was suspended in June 2014.

According to the complaint:

Andrew Davis, Kathy's husband, told police he found his wife unresponsive with a needle and rubber tourniquet in her hand. He said he knew of her heroin addiction and was trying to get her clean.

Investigators found a text on Davis' cellphone from two days earlier that read: "Do you have anything."

Vranish replied: "How much you need." The texts picked up the next day, with Davis saying she had $70 to buy "2 points," meaning two-tenths of a gram.

Vranish replied: "OK I'm weighing it up right now for you. It will be ready in five minutes." The two then arranged to meet.