Parents of 2-year-old girl who died from fentanyl overdose charged with murder

The parents of a 2-year-old girl who died of a fentanyl overdose in the family's California apartment have been charged with murder, according to the San Francisco district attorney, who alleged the couple showed a "conscious disregard for human life."

The charges come two months after the toddler's death, which the medical examiner ruled to be acute fentanyl toxicity, according to San Francisco District Attorney Brooke Jenkins.

San Francisco police officers responded to her home on the morning of Feb. 12 in response to a 911 call that a child was not breathing, prosecutors said. Medics pronounced the girl dead at the scene and "observed signs of rigor mortis and lividity, indicating the child had been dead for several hours," the district attorney's office said in a press release.

The child's parents -- 38-year-old Michelle Price and her boyfriend, 43-year-old Steve Ramirez -- were both initially charged with felony child endangerment, possession of fentanyl and possession of drug paraphernalia, prosecutors said.

On Wednesday, Jenkins announced that her office filed an amended complaint that additionally charges both parents with second-degree murder and allegations that they willfully caused harm or injury resulting in death to a child.

A judge issued bench warrants for the parents after they failed to show up to court for a hearing on the amended complaint Thursday, court records show.

Price is being represented by a public defender. The San Francisco Public Defender's Office declined to comment on her case at this time. ABC News has reached out to Ramirez's attorney for comment.

Jenkins said this marks the first homicide case her office has filed in connection with a fatal fentanyl overdose.

"There were drug paraphernalia loosely around this apartment, as well as different amounts of fentanyl loosely sitting out in the open," she said at a press briefing on Wednesday.

Prosecutors said a used Narcan container was observed at the scene and that the toxicology analysis showed naloxone (Narcan), in addition to fentanyl, in the toddler's bloodstream.

Jenkins said the presence and use of Narcan suggested that the parents were aware of the danger of fentanyl and "still allowed their child to have access to that drug."

She said she believes the murder charges are appropriate, saying, "It was clear to me that these parents were aware of its lethality and the danger of fentanyl."

The district attorney said the toxicology report was the "most significant piece of evidence" her office needed before filing the murder charges. The office had also been waiting for the cause of death, she said.

"Our theory will be a conscious disregard for human life -- not that this was obviously an intentional death that occurred or intentional killing, but that they were, again, aware of the dangers that fentanyl posed and still allowed it to be available to this child in a manner that we believe was reckless," Jenkins said.

When officers arrived at the residence on Feb. 12, Ramirez allegedly attempted to flee on a bicycle, resisted arrest and injured an officer while being detained, prosecutors said. Officers found two glass pipes near him and a third in a bag attached to his bike, prosecutors said. He was also charged with an additional count of possession of drug paraphernalia and resisting, obstructing and delaying a peace officer.

"High levels" of fentanyl and methamphetamine were determined to be in the blood of both Price and Ramirez at the time they were arrested, prosecutors said.

"I want to be clear to parents who may be struggling with substance abuse disorder -- first and foremost, we must protect the children in San Francisco, and this is a job that I take extremely seriously," Jenkins said.