Bay Area Murder Suspect Arrested in Calexico in Connection to Death of 18-Year-Old Marissa DiNapoli

CALEXICO — A man wanted in connection with the murder of 18-year-old Marissa DiNapoli was arrested in Calexico over the weekend, following a multi-agency investigation that spanned several jurisdictions.

Martin Mendoza, Jr., 20, was taken into custody by agents from the U.S. Marshals Service at the Calexico West Port of Entry on Saturday, July 6, at approximately 5:10 p.m., according to the Imperial County Sheriff’s Office. Mendoza was booked into Imperial County Jail without bail on an out-of-county warrant issued by the Morgan Hill Police Department.

The arrest stems from a homicide investigation led by Morgan Hill PD after DiNapoli, a San Jose resident with family ties to the Imperial Valley, was reported missing on June 30. Her last known contact was a text message to relatives on June 28, stating she planned to stay overnight with a friend.

Investigators determined DiNapoli was last seen around 9:45 a.m. on June 29 leaving a residence in Morgan Hill with Mendoza. Her vehicle was later found abandoned nearby. Mendoza, initially uncooperative with investigators, was identified as a person of interest and a warrant for his arrest was issued.

The search for Mendoza included public outreach efforts, with authorities stating he was believed to be driving a white Toyota Camry with California license plates.

DiNapoli’s body was discovered on the evening of July 2. The Santa Clara County Coroner’s Office confirmed her identity the following day.

“This arrest marks a significant step toward justice in a case that has devastated Marissa’s loved ones and shaken our entire community,” the Morgan Hill Police Department said in a statement.

More than 30 investigators from the Morgan Hill Police Department, Santa Clara County District Attorney’s Office, Santa Clara County Sheriff’s Department, and the FBI contributed to the investigation.

“This is not the outcome any of us wanted and we are heartbroken by this news,” Morgan Hill PD added. “Marissa was a vibrant member of our community with a bright future ahead of her. To Marissa’s family, our arms are around you. Our whole Department is here to support you during this unimaginable time.”

In a separate statement, the department noted, “While Mendoza’s arrest may bring a measure of relief, it does not ease the heartbreak we all continue to feel. Marissa was a radiant, compassionate young woman with a future full of promise. Her loss is profound, and our grief is shared.”

In the aftermath of the tragedy, law enforcement hosted community healing events focused on promoting healthy relationships and raising awareness about domestic violence.

The DiNapoli family also issued a public statement.

“The loss of our beloved Marissa deeply saddens us, and at this time, our family kindly asks for privacy as we grieve and navigate this difficult journey,” the statement read. “We appreciate the love and support from those who have reached out to us.”

The family asked that no fundraising efforts be started in Marissa’s name and instead encouraged the community to honor her memory with prayers, kind words, and by sharing cherished memories.

Authorities continue to urge the public to keep DiNapoli’s family in their thoughts, emphasizing that through compassion, education, and unity, the community can work to prevent future tragedies.