The mother of a toddler who died of fentanyl poisoning during her parents’ New Year’s drug exchange pleaded guilty to child abuse resulting in death and drug possession with intent to distribute, a Class 3 felony.

Nicole Casias,32, and the child’s father, 33-year-old Alonzo Montoya, were originally charged with seven counts in Aviyana Montoya’s death, including first-degree murder of a victim under 12 by a person in the position of trust and child abuse resulting in death.

First responders found the 22-month old baby unresponsive in her crib. She had ingested 10 times the amount of fentanyl it would take to kill an adult sometime between Jan. 1 and Jan. 2, 2022.

The child is believed to be the first person to die from fentanyl poisoning that year, the peak of drug overdose fatalities in Colorado. Through a 12-month period ending in January 2022, roughly 1,930 people died of overdoses in Colorado, according to the Centers for Disease Prevention and Control. It would get worse through February of that year, when, also looking through a 12-month period, drug overdoses killed nearly 2,000 people in the state.       

Aviyana’s autopsy revealed that she had continually been exposed to cocaine, meth and marijuana smoke in the three months prior to her death.

An Adams County grand jury found that the couple sold drugs out of their apartment at 345 S. 7th Ave. in Brighton “on a daily, on-going basis, at all hours of the day and night” and kept the drugs in close proximity to their children, even allowing other people to get high in the presence of Aviyana and her sister.

The couple was indicted in September 2022.

Alonzo Montoya, 33, was convicted of five charges — racketeering, conspiracy and child abuse counts, including recklessly causing a death — following a two-week trial in January. He was sentenced in April to 40 years in prison. 

The trials of both parents hit a snag when an Adams County judge dismissed first-degree murder charges against the couple in December 2022.

Chief District Judge Donald Quick of the 17th Judicial District ruled the evidence did not support allegations that Montoya and Casias “knowingly caused the death” of their daughter.

“There was not evidence that either defendant gave fentanyl to the child, knew the child had consumed fentanyl or had let the child roam free overnight with fentanyl being available within easy reach,” Quick’s Dec. 1 order said. “If so, the court could have found evidence establishing probable cause for the murder charge.”

While Quick found no evidence of pre-meditation, he said he could not ignore the evidence showing the couple neglected the infant for hours as she died gasping for air.

“However, the court must also consider the evidence that neither parent checked in on this child for 14 hours while they used and sold drugs (and went about the apartment),” Quick said. “For over six hours, this child struggled to stay alive.”

“She cried, coughed, and gasped for breath as her lungs filled with fluids. Yet, no one came to help her. This evidence is shocking in its disregard for the child’s wellbeing,” the judge said. 

The judge added: “But, it does not demonstrate that the defendants were practically certain that their acts would result in the victim’s death. In considering this evidence, even in conjunction with the exposure to fentanyl before the child was put to bed, the court still does not find this evidence supports a finding of probable cause that the parents ‘knowingly caused the death’ of their child.”

Casias’ sentencing is scheduled for 8:30 a.m. July 16, where she faces from 16 to 32 years in prison. 

At the time of her death, Aviyana’s death was among several overdoses cases that highlighted the pervasiveness of fentanyl, a dangerous and powerful opioid that was developed to treat intense pain from ailments like cancer but has since been mixed with other drugs in the illegal drug supply because it is inexpensive.

And, bucking a national downward trend, more people died from drug overdoses in Colorado from December 2022 to December 2023 than the previous one-year period, a sobering reminder that the crisis is still hammering the western states, though it is showing signs of easing in the east.

Colorado, which showed a 3.9% spike in what’s called “predicted” data, was ranked No. 10 among the states with the highest rate of increase. This “predictive” method takes into account and adjusts for incomplete, provisional drug overdose data, which often undercounts the final numbers.

CDC data put the predicted cases through December 2023 in Colorado at 1,928. That number was 1,856 through the same period in 2022.

Reporter Sage Kelley contributed to this article.