10-Year-Old Boy's Fentanyl Death Haunts Family, IE Community

RANCHO CUCAMONGA, CA — It's still unclear exactly how a 10-year-old Nathaniel Angel Castro Mendoza of Rancho Cucamonga was exposed to a fatal fentanyl dose in his home, but a woman who lived at the residence was sentenced this week to six years in prison for her role in his death.

Christina Veronica Alvarez, 33, appeared Monday in the Rancho Cucamonga Division of the San Bernardino County Superior Court before the Hon. Judge M. Dest for sentencing.

Last month, at the same courthouse, Alvarez entered a plea of no contest to one count of felony child abuse likely to cause great bodily harm, and she admitted to an associated enhancement of willful harm or injury resulting in death.

There was never enough evidence in the case to bring a murder charge against Alvarez, who was the girlfriend of Nathaniel's uncle.

The boy's tragic death occurred in December 2024 after San Bernardino County sheriff's deputies were called to the 9000 block of Arrow Route in Rancho Cucamonga regarding an unresponsive 10-year-old child.

Despite life-saving efforts, the boy, identified as Nathaniel, died.

It took approximately two months before the San Bernardino County coroner determined Nathaniel died from fentanyl and xylazine toxicity.

During the law enforcement investigation, Alvarez was identified as the suspect. According to the sheriff's department, she "possessed and stored fentanyl in a manner that led to the victim's death."

Last year, NewsNation interviewed Nathaniel's parents, Marcy Castro and Miguel Mendoza.

According to the couple, Nathaniel's last day was just like any other. The boy who loved baseball, wrestling, and Captain America came home from school, rode his bike, played outside, ate his dinner, and went to bed.

At about 11 p.m., Nathaniel got up to use the bathroom, but nothing out of the ordinary was noticed by his family. It was the last time anyone would see him alive.

Marcy told NewsNation that many thoughts have run through her mind about how Nathaniel was exposed to the fentanyl.

"In my heart, I feel like maybe it was done purposely, but obviously we can't prove that," she said.

"The only reason we feel that way is ... there were many other people in the household, and for some reason only our son was affected by it," Miguel explained.

Alvarez has two children of her own. The trio lived under the same roof as Nathaniel and his parents. The shrimp dinner that Nathaniel ate before dying was brought in by Alvarez. She and her children allegedly ate the dinner too.

Nathaniel's parents suspect their child's food was tainted.

During court proceedings for Alvarez, her defense team requested that she be considered for a mental health diversion, a court-authorized process that allows eligible defendants with qualifying mental health disorders to receive treatment in lieu of traditional criminal prosecution.

On January 9, 2026, after reviewing the request, the court denied it. On March 19, Alvarez entered her no-contest plea to felony child abuse and admitted willful harm or injury resulting in death.

During the sheriff's investigation into Alvarez, the sheriff's department released a statement saying it "recognizes the profound impact this case has had on the victim’s family and the community. Crimes involving fentanyl, particularly those that endanger children, remain a significant public safety concern."