Vicente David Romero is accused of knowingly supplying a woman with fentanyl in June 2020.
MURRIETA, Calif. (KABC) -- Fentanyl is 100 times stronger than morphine and a substance that can kill someone with just one pill.
It is a premise prosecutors with the Riverside County District Attorney's Office is using to charge fentanyl dealers and suppliers with murder.
"Ladies and gentlemen, you are going to hear about the murder of Kelsey King," said Riverside County District Deputy District Attorney Jerry Pfohl during his opening arguments Wednesday at the Southwest Justice Center in Murrieta.
Pfohl accused Vicente David Romero of knowingly supplying King with fentanyl in June 2020.
King died after ingesting half a pill with Romero. He is now on trial for second-degree murder.
"He bought six pills the day prior ... now the defendant knew that Kelsey King had never taken fentanyl, it was actually something he asked her," said Pfohl.
However, Romero's defense attorney claims his client believed the pills he purchased were Oxycodone and that prior to sharing a single pill with King, the two had been doing meth.
"Two lost souls, experimenting with drugs, not cautious with what they're doing ... they get the wrong drug ... one gets sick and one dies," Romero's defense attorney said.
Since 2021, the cheap synthetic opioid has been responsible for 6,000 deaths in California, according to the latest data. The murder trial is a first for Riverside County as it tries to crackdown on the opioid crisis.
"This is the first of 23 cases that are moving forward through the justice system right now related to fentanyl-related deaths," said Brooke Beare, a spokesperson with the Riverside County District Attorney's Office.
The case has caught the attention of Matt Capelouto, whose daughter died after ingesting a fentanyl-laced pill in 2019.
A bill named "Alexandra's Law," which was named after his daughter, would have mandated drug dealers be issued warning about the possibility of being prosecuted for murder if their product killed someone.
The bill failed after it was denied a full house vote by members of the state's public safety committee.
"They have not passed a single bill that will help law enforcement hold these death dealers accountable, and that's why these cases are going to be the exception, and not the rule, until they pass meaningful legislation," said Capelouto, who also founded the drug awareness website called DrugInducedHomicide.org.
If Romero is convicted, he is facing 15 years to life in prison.