San Mateo man charged with murder for fentanyl death

Arellano was arraigned Jan. 10 and was appointed a private defender program lawyer. He remains in custody on no bail status.

Arellano — who did not sell drugs, only made the purchase for himself and the victim, Wagstaffe said — is allegedly a fentanyl addict himself who had overdosed before and was aware of the dangers of the drug.

On the occasion of one of those overdoses, the San Mateo Police Department had admonished Arellano that fentanyl was deadly and that it could lead, in the future, to a murder prosecution should he provide it to another person who died, according to Wagstaffe.

Dahbour had also overdosed twice before, Wagstaffe said.

The San Mateo Police Department began issuing those warnings in 2024, but they’ve become statewide policy following the passage of Proposition 36, designed to crack down on fentanyl and shoplifting.

“We want the message to go out to dealers — you will be prosecuted,” Wagstaffe said.

This follows an increase in prosecution of providers of deathly drugs across the state of California. The specific theory of homicide liability in cases like these was originally pioneered by the Riverside District Attorney’s Office and spread across the state, Wagstaffe said.

It’s the second such case in San Mateo County. The first involved a 56-year-old Daly City man, Phillip Ng, who was charged with murder for the May 2023 overdose of a 29-year-old Harvard graduate who died from fentanyl intoxication.

The victim, Sarah Tillman, allegedly began to purchase what she believed to be Oxycodone from Ng in the weeks and days leading up to her death, prosecutors said. She had allegedly previously alerted Ng to the fact that the drugs he was selling could be adulterated with fentanyl, making him liable for the death in the eyes of the DA’s Office.

Unfortunately, Wagstaffe said he believed the DA’s Office would continue to prosecute such crimes in San Mateo County.

“I pray not,” he said. “I suspect we will.”