Overview

• Full name: Allen Talmadge Mathews
• Age when last seen: 80 years old
• Date of birth: July 5, 1917
• Date last seen: May 21, 1998
• Last known location: San Leandro, Alameda County, California (reporting jurisdiction; precise location not publicly specified)
• Sex: Male
• Race: Black
• Height: 5 feet 7 inches
• Weight: 147 pounds
• Hair color: Gray
• Eye color: Brown
• Distinguishing characteristic: Wore glasses
• Medical condition: Dementia
• Case classification: Missing person
• Current publicly documented status: Listed as missing by the California Department of Justice; no verified resolution located
• Investigating agency: San Leandro Police Department
• Police case number: 98-5387

Case circumstances: Allen Mathews was last seen on May 21, 1998. Authorities documented that he had dementia, but the publicly accessible record does not explain the circumstances of his disappearance, whether he left a residence or another location, or whether anyone witnessed his departure.

Detailed Case Breakdown

Allen Talmadge Mathews: The Unsolved 1998 Disappearance in San Leandro, California

On May 21, 1998, Allen Talmadge Mathews disappeared in California. He was 80 years old and living with dementia, a condition that made his disappearance particularly concerning. More than 28 years later, the circumstances surrounding his disappearance remain publicly unresolved.

The California Department of Justice maintains an official missing-person record for Mathews, identifying the San Leandro Police Department as the reporting agency. Although the available record establishes when he was last seen, it provides few details about what happened that day or where he may have gone.

His case remains an important reminder of the dangers faced by vulnerable missing adults and the lasting uncertainty that accompanies disappearances without publicly documented resolutions.

Case Summary

• Full name: Allen Talmadge Mathews
• Age when last seen: 80 years old
• Date of birth: July 5, 1917
• Date last seen: May 21, 1998
• Last known location: San Leandro, Alameda County, California (reporting jurisdiction; precise location not publicly specified)
• Sex: Male
• Race: Black
• Height: 5 feet 7 inches
• Weight: 147 pounds
• Hair color: Gray
• Eye color: Brown
• Distinguishing characteristic: Wore glasses
• Medical condition: Dementia
• Case classification: Missing person
• Current publicly documented status: Listed as missing by the California Department of Justice; no verified resolution located
• Investigating agency: San Leandro Police Department
• Police case number: 98-5387

Case circumstances: Allen Mathews was last seen on May 21, 1998. Authorities documented that he had dementia, but the publicly accessible record does not explain the circumstances of his disappearance, whether he left a residence or another location, or whether anyone witnessed his departure.

Background: Who Was Allen Talmadge Mathews?

Allen Talmadge Mathews was born on July 5, 1917. At the time of his disappearance in May 1998, he was 80 years old and approaching his 81st birthday.

According to his official California missing-person record, Mathews was a Black man with gray hair and brown eyes. He stood approximately 5 feet 7 inches tall, weighed 147 pounds, and wore glasses.

One of the most significant details in his case was his dementia diagnosis.

Dementia can affect memory, orientation, judgment, and a person’s ability to recognize familiar surroundings. For someone experiencing these symptoms, becoming separated from familiar people or places can create serious safety concerns.

However, the public record does not establish how advanced Mathews’s condition was or how it affected his daily activities. It would therefore be inappropriate to assume that he became disoriented or wandered away.

Little additional biographical information has been located in reliable public sources. His occupation, family relationships, earlier life, and daily routines have not been independently established.

The absence of these details should not overshadow the central fact of the case: an elderly man with a documented cognitive condition disappeared, and the publicly available information does not explain what happened to him.

The Disappearance on May 21, 1998

May 21, 1998, is the last-seen date recorded by the California Department of Justice.

The San Leandro Police Department is identified as the reporting agency, connecting the investigation to San Leandro in Alameda County, California.

However, the official listing does not provide a street address, neighborhood, residence, business, or other specific location where Mathews was last observed.

The record also does not identify the person who last saw him, the time of day he disappeared, or what he was wearing.

These missing details limit what can responsibly be reconstructed about the events of May 21.

There is no verified public account establishing whether Mathews was walking, using public transportation, traveling with another person, or attempting to reach a particular destination.

Similarly, there is no publicly verified information showing whether he had identification, money, medication, or personal belongings with him.

Because Mathews had dementia, his medical vulnerability is an important aspect of the case. Nevertheless, his condition alone does not establish the reason for his disappearance.

The confirmed facts remain limited: Mathews was last seen on May 21, 1998, and authorities subsequently documented him as a missing person.

Investigation History and Available Evidence

San Leandro Police Department Investigation

The San Leandro Police Department is the law enforcement agency identified in Mathews’s California Department of Justice missing-person listing.

The official record assigns the case number 98-5387.

This reference number provides an important means of identifying the investigation when contacting authorities or submitting potentially relevant information.

The publicly accessible listing does not describe the initial police response, the date a missing-person report was filed, or the investigative steps undertaken after Mathews disappeared.

It also does not establish whether officers conducted neighborhood searches, interviewed specific witnesses, examined transportation records, or coordinated searches with surrounding jurisdictions.

Those investigative activities may have occurred, but they cannot be presented as confirmed without supporting documentation.

Physical Evidence and Forensic Information

No publicly verified case-specific information was located describing recovered clothing, personal belongings, vehicles, or other physical evidence associated with Mathews’s disappearance.

The California Department of Justice record indicates that dental X-rays were not available in the information recorded for his case.

That detail does not establish whether other identification records, medical records, fingerprints, or biological reference samples exist.

No confirmed public report was located describing DNA testing, forensic genetic genealogy, or a match between Mathews and unidentified human remains.

Witnesses and Potential Leads

The available official case record does not identify a publicly named witness, suspect, or person of interest.

No verified witness statement was located describing Mathews’s movements immediately before or after May 21, 1998.

The absence of publicly available witness information does not necessarily mean investigators received no tips or interviewed no witnesses. It means those details could not be established from the accessible sources.

Theories and Unresolved Questions

Several possibilities may be considered when examining the disappearance of an older adult with dementia. These are general investigative considerations, not confirmed explanations for what happened to Mathews.

Could Mathews Have Become Disoriented?

Because Mathews had dementia, one possibility is that he became confused or lost while away from a familiar environment.

Individuals experiencing cognitive impairment may have difficulty navigating or communicating their personal information.

However, there is no verified public evidence establishing that Mathews wandered away, became lost, or experienced a particular episode of disorientation on the day he disappeared.

Could He Have Experienced a Medical Emergency?

Another possibility in an unexplained disappearance involving a medically vulnerable person is an accident or medical emergency.

There is no confirmed public evidence establishing that Mathews suffered an injury, medical crisis, or accidental death.

His disappearance should not be classified as a fatal incident without supporting evidence.

Was Foul Play Involved?

The available official record classifies Mathews as a missing person, not as a confirmed homicide victim.

No verified public evidence was located identifying criminal involvement, a suspect, a motive, or an arrest related to his disappearance.

Foul play cannot be asserted simply because the disappearance remains unexplained.

Questions That Remain Unanswered

Important unresolved questions include the precise location where Mathews was last seen, who last had contact with him, how he was traveling, and whether any credible sightings were reported afterward.

Other questions concern whether physical evidence was recovered, whether investigators compared his information with unidentified-person records, and whether additional case records exist outside the publicly accessible listing.

These questions illustrate the limitations of the available information rather than proving any particular theory.

Latest Publicly Available Investigative Updates

As of October 26, 2026, the California Department of Justice missing-person listing remains the principal verified public source located for Allen Talmadge Mathews.

The listing continues to identify his May 21, 1998, disappearance and the San Leandro Police Department’s case number.

No publicly confirmed recent investigative developments were located during this review.

Specifically, no verified recent announcement was found documenting an arrest, criminal charges, identification of remains, DNA identification, forensic genealogy breakthrough, or official resolution of the disappearance.

No case-specific public announcement of a renewed search, newly identified suspect, or significant cold-case discovery could be verified.

The continuing availability of the state missing-person listing should not be mistaken for evidence that a new investigation or breakthrough has occurred.

Likewise, the lack of a publicly announced development does not establish that law enforcement has stopped working on the case.

The precise internal investigative status would require confirmation directly from the San Leandro Police Department.

Conclusion: Remembering Allen Talmadge Mathews

Allen Talmadge Mathews disappeared on May 21, 1998, at the age of 80. He was a medically vulnerable older adult whose disappearance has remained publicly unexplained for more than two decades.

His case has relatively little accessible historical documentation. The official record establishes his identity, physical description, dementia diagnosis, last-seen date, and reporting police agency, but it does not provide a detailed account of the events leading to his disappearance.

Without additional verified evidence, no conclusion can responsibly be reached about whether Mathews became lost, suffered an accident, encountered another person, or experienced some other event.

Anyone with credible information about Allen Talmadge Mathews’s disappearance, his whereabouts after May 21, 1998, or evidence potentially relevant to the investigation is encouraged to contact the San Leandro Police Department.

When contacting authorities, reference case number 98-5387 to help identify the correct missing-person investigation.

Even after many years, information that clarifies a missing person’s final known movements may be valuable to investigators and to those seeking answers.