Prosecutors say the driver was speeding, may have inhaled chemicals from an air duster and will remain jailed as the case moves ahead.
FRESNO, Calif. — The criminal case tied to the death of 15-year-old Juliani Moreno widened Friday after Fresno County prosecutors added an intoxication-related manslaughter charge against the woman accused of hitting him in Parlier earlier this week.
Prosecutors said 35-year-old Tiffany Mercado pleaded not guilty in Fresno County Superior Court after investigators provided new information about the March 10 crash. Authorities told the court they believe Mercado drove through a stop sign at high speed, struck Moreno and another teen in a crosswalk, then continued roughly 1,000 feet before crashing near businesses. The added charge shifted the case from a fatal traffic collision into a broader prosecution focused on alleged impairment, speed and Mercado’s prior criminal record.
According to investigators, the crash happened at the intersection of Mendocino and Parlier avenues in Parlier. Moreno, a 15-year-old from the city, was pronounced dead at the scene. His girlfriend survived and later described the moment to local reporters, saying the pair had been walking hand in hand when the car came at them. Officials have said the second teen was injured. In court, prosecutor Stephen Ueltzen said the investigation indicated Mercado was traveling between 80 and 100 mph when she entered the intersection. He also said evidence gathered after the crash suggested Mercado got out of the vehicle, went to the trunk and handled an item that investigators later identified as an air duster can.
That detail became central to Friday’s hearing. Ueltzen said the can had been purchased the same day and was about half used. He said it contained difluoroethane, a chemical that can be inhaled for intoxicating effects. Police had already said they believed Mercado was under the influence, but had ruled out alcohol as a cause. Local television footage from the crash scene showed Mercado appearing unsteady during a sobriety test, though toxicology results were still pending. Defense attorneys noted in court that Mercado’s earlier convictions were not related to driving under the influence. Even so, the judge cited what was described as an extensive and violent criminal history while ordering that Mercado remain jailed without bail.
The background of that criminal record has drawn nearly as much public attention as the crash itself. Reporting by local outlets said Mercado had prior felony convictions in San Bernardino County and had been sentenced in April 2024 to six years in prison in a robbery-related case. She was released to post-release community supervision on Jan. 2, 2026. San Bernardino County District Attorney Jason Anderson told reporters that, in his view, Moreno’s death was preventable because Mercado should still have been in custody. The California Department of Corrections and Rehabilitation, responding to questions from another outlet, said she had served the sentence required by law and was not released early. That disagreement has added a second layer to the case, one that reaches beyond the crash scene into a debate over sentencing credits and supervision rules.
The human cost has remained at the center of the proceedings. Moreno had recently transferred to Immanuel High School, where friends and school leaders remembered him as gentle, warm and devoted to football. By Saturday night, hundreds of people gathered at a vigil in Parlier to mourn him. Residents lit candles, hugged family members and spoke about the city’s sense of loss. Many also linked the tragedy to broader safety concerns on Mendocino Avenue, where neighbors said speeding has long frightened people who walk the corridor. The crash site itself became a memorial, with candles spelling out “Long Live Juliani.”
For now, the case remains in an early stage. Authorities have said the investigation is continuing and that additional reports, including toxicology findings, are still pending. Local reporting said Mercado could face as much as 26 years in prison if convicted on the amended charges. Her next court appearances were scheduled for March 18 and March 25, dates that Moreno’s family and the Parlier community are likely to follow closely as they look for answers in the weeks ahead.
As of Monday, Mercado remained in custody and the city was still mourning Moreno. The next formal step is a pair of court hearings this week in Fresno County.
Author note: Last updated March 16, 2026.