Overview

• Full name: Carlos Diaz Martinez (also listed as Carlos DiazMartinez)
• Other names: Carlos Diaz, Carlos Alberto Diaz Martinez, Carlos A. Martinez
• Nickname: Peka
• Age when missing: 35
• Date of birth: September 11, 1988
• Last seen: December 30, 2023, approximately 6:40 p.m.
• Last known location: His residence in Fremont, Alameda County, California
• Classification: Missing person
• Current status: Publicly listed as missing; whereabouts unknown
• Investigating agency: Fremont Police Department
• Police case number: 240101008
• NamUs reference: MP115776
• Physical description: Hispanic male, approximately 5 feet 5 inches tall, 135–140 pounds, black hair, brown eyes, shoulder-length or longer hair, and a goatee
• Distinguishing features: Mole on left cheek and gauges in both ears
• Clothing: Brown shirt and jeans; possibly red skater shoes
• Possible belongings: Blue backpack

Main circumstances: Carlos left his residence on the evening of December 30, 2023. A possible sighting in Newark several weeks later was never confirmed. Authorities have not publicly established his subsequent movements or current whereabouts.

Detailed Case Breakdown

Carlos DiazMartinez Missing in Fremont, California: The Unsolved December 2023 Disappearance

On December 30, 2023, 35-year-old Carlos DiazMartinez left his residence in Fremont, California, at approximately 6:40 p.m. He was wearing a brown shirt and jeans and may have been carrying a blue backpack. What happened after he left remains an unanswered question.

Carlos, also known as Carlos Diaz Martinez and by the nickname “Peka,” was familiar with the Bay Area skateboarding community. He had connections in Fremont, San Francisco, and San Jose. Weeks after his disappearance, a possible sighting in nearby Newark offered a potential lead, but police were unable to confirm it.

More than two years later, Carlos remains publicly listed as missing by the Fremont Police Department and the California Department of Justice. His disappearance has not been officially classified as a homicide, and authorities have not publicly established what caused him to vanish.

Case Summary

• Full name: Carlos Diaz Martinez (also listed as Carlos DiazMartinez)
• Other names: Carlos Diaz, Carlos Alberto Diaz Martinez, Carlos A. Martinez
• Nickname: Peka
• Age when missing: 35
• Date of birth: September 11, 1988
• Last seen: December 30, 2023, approximately 6:40 p.m.
• Last known location: His residence in Fremont, Alameda County, California
• Classification: Missing person
• Current status: Publicly listed as missing; whereabouts unknown
• Investigating agency: Fremont Police Department
• Police case number: 240101008
• NamUs reference: MP115776
• Physical description: Hispanic male, approximately 5 feet 5 inches tall, 135–140 pounds, black hair, brown eyes, shoulder-length or longer hair, and a goatee
• Distinguishing features: Mole on left cheek and gauges in both ears
• Clothing: Brown shirt and jeans; possibly red skater shoes
• Possible belongings: Blue backpack

Main circumstances: Carlos left his residence on the evening of December 30, 2023. A possible sighting in Newark several weeks later was never confirmed. Authorities have not publicly established his subsequent movements or current whereabouts.

Background: Who Was Carlos DiazMartinez?

Carlos DiazMartinez was 35 years old when he disappeared from Fremont, a city in Alameda County in California’s East Bay region.

The Fremont Police Department identifies Carlos as a skateboarder who regularly visited local skate parks. This detail provides an important connection to the places and communities where people may have encountered him before his disappearance.

Carlos also had friends in Fremont, San Francisco, and San Jose. These connections extended across several Bay Area communities and may be relevant to anyone attempting to recall an encounter with him around the time he went missing.

Authorities have released several identifying details. Carlos had black hair that reached his shoulders or longer, a goatee, gauges in both ears, and a mole on his left cheek. His nickname, Peka, may also help people recognize him.

Publicly available investigative profiles provide limited information about his occupation, family background, education, or personal circumstances. Those details should not be assumed or embellished.

What is established is that Carlos had a recognizable appearance, an interest in skateboarding, and connections across the Bay Area. Those characteristics remain important to public efforts to locate him.

December 30, 2023: The Disappearance

According to the Fremont Police Department, Carlos left his residence at approximately 6:40 p.m. on Saturday, December 30, 2023.

He was last seen wearing a brown shirt and jeans. Police also reported that he may have been wearing red skater shoes and carrying a blue backpack.

The available official information does not specify his intended destination, whether he had arranged to meet anyone, or how he planned to travel.

It also does not establish whether Carlos left on foot, used public transportation, or obtained a ride after leaving his residence.

These missing details make it difficult to reconstruct his movements after 6:40 p.m.

There is no publicly verified account establishing where Carlos went immediately afterward or whom he may have encountered.

His departure from home is a confirmed part of the case history. What occurred afterward remains unknown.

Investigation History and Available Evidence

Fremont Police Department Investigation

The Fremont Police Department is the primary investigating agency responsible for Carlos’s disappearance.

The department maintains a dedicated missing-person profile for him and identifies the official police case number as 240101008.

The California Department of Justice also maintains an official missing-person record containing his identifying characteristics, aliases, last-contact date, and investigating agency.

These records provide a means for law enforcement and members of the public to identify Carlos and direct information to the appropriate investigators.

However, the public profiles do not provide a detailed chronology of investigative activities, including interviews, surveillance reviews, neighborhood searches, or searches of nearby public areas.

The absence of those details from public records does not establish that such investigative work was never conducted.

Possible Newark Sighting

One of the few publicly disclosed potential leads concerns a reported sighting in Newark, California.

According to the Fremont Police Department, several weeks after Carlos left his residence, it was believed that he had been seen in Newark.

Police explicitly state that the sighting could not be confirmed.

The available information does not identify the individual who reported the possible encounter, the precise location, or the exact date.

Because the sighting remains unverified, it cannot establish that Carlos was alive and present in Newark at that time.

Nevertheless, the report is an important part of the publicly documented case history because it suggests a possible direction investigators may have considered.

Physical and Forensic Evidence

The publicly accessible police and state records do not identify recovered personal belongings, forensic evidence, confirmed surveillance footage, or a verified location associated with Carlos after his disappearance.

No publicly confirmed DNA identification, genetic genealogy result, or identification of remains was located in the reviewed material.

Likewise, the available records do not establish that his possible backpack, clothing, or shoes were recovered.

These are limitations of publicly available information, not proof that investigators possess no additional evidence.

Suspects, Arrests, and Criminal Proceedings

No suspect or person of interest has been publicly identified in the reviewed official case information.

No arrest, criminal charge, or court proceeding directly connected to Carlos’s disappearance could be verified.

There is also no publicly confirmed finding that he was abducted, assaulted, or killed.

Accordingly, the case must continue to be described as a missing-person investigation rather than a confirmed homicide.

Theories and Unresolved Questions

Carlos’s disappearance leaves several significant questions unanswered. Although different explanations may be possible, the publicly available evidence does not support selecting one as the established explanation.

Did Carlos Travel to Another Bay Area Community?

Carlos had friends in Fremont, San Francisco, and San Jose, and police described him as someone who frequented skate parks.

Those connections identify communities where people may have known or encountered him.

However, there is no confirmed public evidence that he traveled to any of those cities after December 30, 2023.

His friendships and recreational interests should not be treated as proof of his destination.

Was the Newark Sighting Accurate?

The reported Newark sighting raises the possibility that Carlos was seen after leaving his residence.

Yet the police department’s inability to verify that report prevents it from being considered a confirmed subsequent sighting.

The exact circumstances of the report remain unknown.

Did Carlos Leave Voluntarily?

Police confirm that Carlos left his residence, but that fact alone does not establish why he left or whether he intended to remain away.

There is no publicly verified explanation for his departure or continued absence.

Similarly, there is no reliable public evidence establishing that another person forced him to leave.

Could Foul Play Have Occurred?

Foul play is one possible explanation that can arise in an unresolved disappearance, but possibility is not evidence.

The reviewed official records do not identify signs of violence, a suspect, or a criminal act involving Carlos.

There is therefore no factual basis for presenting his disappearance as a confirmed kidnapping or homicide.

The central unanswered question remains what happened to Carlos after he left his Fremont residence on December 30, 2023.

Latest Publicly Available Investigative Updates

Information reviewed through October 28, 2026

Carlos DiazMartinez continues to appear on the Fremont Police Department’s public missing-person roster and in the California Department of Justice missing-person database.

The police department’s individual case page continues to describe his December 2023 departure and the unconfirmed possible sighting in Newark.

Public awareness listings also identify him as a missing person and reference NamUs case MP115776.

These continuing listings demonstrate that his case remains publicly documented. They do not, by themselves, establish that investigators have obtained new evidence.

No publicly confirmed recent investigative breakthroughs, arrests, recovery of remains, verified sightings, or case resolution were located in the sources reviewed.

No confirmed public announcement of a new forensic finding, genetic genealogy result, or renewed search operation was identified.

The publicly available information therefore leaves Carlos’s disappearance unresolved.

Conclusion: The Search for Carlos DiazMartinez Continues

Carlos DiazMartinez was 35 years old when he left his Fremont residence on December 30, 2023. Since that evening, the public record has provided few confirmed answers about his whereabouts.

His distinctive appearance, nickname Peka, interest in skateboarding, and connections across the Bay Area may help someone recognize him or recall information that has not yet reached investigators.

The possible Newark sighting remains unconfirmed, and authorities have not publicly established whether Carlos encountered danger, traveled elsewhere, or experienced some other circumstance that prevented his return.

Anyone who saw Carlos around December 30, 2023, or who has reliable information about his subsequent movements is encouraged to contact the Fremont Police Department at (510) 790-6800.

When contacting investigators, reference case number 240101008.

Even information that appears minor may help authorities establish a more complete account of his movements.

Carlos remains missing, and the questions surrounding his disappearance deserve careful attention grounded in verified facts rather than speculation.