HILLSBORO, NM (KRQE) – After more than a year-long investigation, a nurse was arrested for the death of her fiancé. Deputies in southwest New Mexico claim she tried to make it look like an accident.

“They stayed tenacious, little pit bulls, they grab a hold of it and wouldn’t let go,” explained Sierra County Sheriff Glenn Hamilton, of his investigators’ year-long work into the death of Richard Harris.

It all started with a 911 call from Hillsboro, New Mexico on March 20, 2015.

“I think he’s having a respiratory arrest,” Harris’ fiancé at the time, Kandi Adams, told 911 dispatchers.

“His 02 sat is down to like, about 62 percent, his color is horrible, I need help out here now,” Adams said.

Adams told 911 dispatchers she’s a nurse, and Harris was having a hard time breathing.

EMS told Adams to start CPR until they arrived. Minutes later, Adams told the dispatcher, “Guys, he’s gone!”

However, when paramedics arrived, they said it was clear Harris had been dead for a while. Rigor Mortis had already set in.

At the time, it wasn’t clear yet how Harris died.

“It took us a little while to really uncover some of the inconsistencies, we had to wait obviously for the medical examiners report,” explained Sheriff Hamilton.

Meanwhile, Harris’ son had found Adams had cashed a check from his father’s account for $5,000 just three days after his death.

There was a third red flag. According to investigators, Adams showed Harris’ sons a “will” that she claimed proved Harris left all of his belongings and assets to her.

“She had presented a will, and it did not appear to be his father’s signature on the will,” said Hamilton.

When the medical examiners report came in, deputies said it was clear Adams lied.

She’d worked in the operating room at Mountain View Regional Medical Center in Las Cruces, and had access to Propofol, the sophisticated intravenous drug analysts found was what killed Harris.

“She’s the only one that could have administered those drugs to him,” Hamilton told KRQE News 13.

Armed with evidence, investigators surprised Adams in her Nevada home earlier this month, and arrested her for murder.

Deputies said she changed her story, and later admitted Harris was already dead when she called 911.

Adams was extradited back to New Mexico. She’s charged with murder, tampering with evidence, and two counts of forgery. She’s being held on a $100,000 cash only bond.