A lethal dose of fentanyl is displayed next to a penny for scale. (U.S. Drug Enforcement Administration via Bay City News)

A motion to bring the first murder case in San Francisco against two adults implicated in a baby’s death from fentanyl poisoning has been filed, the District Attorney’s Office said.

Michelle Price, 38, and Steve Ramirez, 43, were charged Wednesday with allegations of murder after a toddler suffered a fatal overdose

The pair had originally been charged with felony child endangerment, being in possession of fentanyl and possessing drug paraphernalia.  

Now a new amended complaint is charging them with second-degree murder and allegations that they willfully caused harm or injury causing death to the child.  

On Feb. 12 just after 5 a.m., San Francisco officers responded to a residence in the 3800 block of 18th Street after a 911 call came in reporting a child not breathing. Paramedics arrived and found a two-year-old child dead. Prosecutors allege the toddler showed signs of rigor mortis and lividity, meaning the child had been dead for several hours.  

Prosecutors are alleging that officers saw drug paraphernalia, a used Narcan container and fentanyl at the residence. There were also allegedly bottles of spoiled milk and stained sheets.  

Officers said the child’s mother, Price, had droopy eyes, slurred speech and showed no emotion. They also accuse Ramirez, Price’s boyfriend, of attempting to flee on a bicycle when police arrived.  

Prosecutors said the medical examiner found both fentanyl and Narcan — an opioid blocker — in the child’s bloodstream. There were no other signs of physical trauma to the child. The cause of death was acute fentanyl toxicity.  

Prosecutors also said high levels of fentanyl and methamphetamine were found in blood draws of both Price and Ramirez.  

The motion to amend the complaint to a murder charge is scheduled to be heard on Thursday, the District Attorney’s Office said.