Overview

Last Seen: January 1, 1975
Location: Potrero/San Diego County, California
Status: Missing; circumstances have been described as suspicious
Investigating Agency: San Diego County Sheriff’s Department

Main circumstances: Joyce was living in Potrero when she disappeared in 1975. She was not formally reported missing until December 15, 1995, approximately 20 years later. Her daughter Kimberly Cozart disappeared separately in 1977. Both disappearances were reported on the same day in 1995, and authorities have not publicly established that the two cases are connected.

Detailed Case Breakdown

Joyce Elizabeth Harper: The Unsolved 1975 Disappearance in Potrero, California

More than half a century after Joyce Elizabeth Harper disappeared in San Diego County, California, investigators are still seeking information that could explain what happened to her. Harper vanished in 1975 while living in Potrero, a small community in southeastern San Diego County near the U.S.-Mexico border.

Her disappearance would become even more unusual two years later, when her teenage daughter, Kimberly Cozart, also disappeared in San Diego County. Both cases remain unresolved.

Very Brief Case Summary

Last Seen: January 1, 1975
Location: Potrero/San Diego County, California
Status: Missing; circumstances have been described as suspicious
Investigating Agency: San Diego County Sheriff’s Department

Main circumstances: Joyce was living in Potrero when she disappeared in 1975. She was not formally reported missing until December 15, 1995, approximately 20 years later. Her daughter Kimberly Cozart disappeared separately in 1977. Both disappearances were reported on the same day in 1995, and authorities have not publicly established that the two cases are connected.

Who Was Joyce Elizabeth Harper?

Joyce Elizabeth Harper was born December 9, 1945, according to the California Department of Justice. She was a white woman with brown hair and brown eyes, approximately 5 feet 3 inches tall and weighing about 120 pounds.

Records indicate that Harper also used the name Joyce Gann and the alias Vivian Ann Maddux.

There is an unresolved discrepancy concerning her age when she disappeared. Based on the December 9, 1945 birth date published by the California Department of Justice, Harper would have been 29 on January 1, 1975. The Charley Project also lists her as 29. However, the San Diego County Sheriff’s Department currently describes Harper as 31 years old at the time of her disappearance.

The 1975 Disappearance of Joyce Harper

Authorities use January 1, 1975 as Joyce Harper’s last-seen or missing date. The California Department of Justice lists her as last seen in San Diego, California, while the San Diego County Sheriff’s Department says she was last known to be living in Potrero, California.

Very little has been publicly released about the circumstances immediately surrounding her disappearance. There is no publicly documented account explaining where she was going, who last saw her, what transportation she may have used, or precisely where in Potrero she was last seen.

Harper apparently disappeared without investigators receiving a missing-person report at the time.

Joyce Was Not Reported Missing Until 1995

One of the most significant circumstances in the case is the approximately two-decade delay before Harper was formally reported missing.

According to the San Diego County Sheriff’s Department, Joyce was reported missing by her daughter on December 15, 1995.

The California Department of Justice currently identifies the Sheriff’s case as 95-087100.

That lengthy gap between the disappearance and the missing-person report potentially complicated the investigation. Witness memories can fade, physical evidence can disappear, records can be lost or destroyed, and people with information may die or become difficult to locate.

The Disappearance of Joyce’s Daughter, Kimberly Cozart

Joyce’s case has another disturbing element. Her teenage daughter, Kimberly Cozart, also known as Kimberly Harper, disappeared approximately two years later.

Kimberly was last seen in Julian, California, in February 1977. She was 15 years old and reportedly lived on Banner Grade Road.

Like her mother, Kimberly was not reported missing at the time she vanished. The two women were ultimately reported missing on the same date — December 15, 1995.

The Charley Project states that it is unclear whether their disappearances are otherwise connected. Both cases remain unresolved.

The fact that a mother and daughter disappeared from different San Diego County communities within roughly two years of each other has inevitably generated questions, but publicly available law-enforcement information does not establish that the same person or event was responsible for both disappearances.

Was Joyce Harper Murdered?

There is currently no public evidence establishing that Joyce Harper was murdered, and her case should not be presented as a confirmed homicide.

The California Department of Justice lists Harper as a missing person, while the Charley Project classifies her as endangered missing and describes the circumstances as suspicious.

The San Diego County Sheriff’s Department includes Joyce’s case within its Cold Case Homicide & Missing Person Investigations program. That placement does not, by itself, mean authorities have determined that she was killed.

No remains publicly identified as Joyce Harper’s have been announced, and authorities have not publicly named a suspect or disclosed a confirmed cause or manner of death.

Current Investigation and Latest Public Information

Joyce Harper’s disappearance remains an active cold-case missing-person investigation.

The San Diego County Sheriff’s Department continues to publicly list Joyce Elizabeth Harper and states that its Homicide Detail and San Diego County Crime Stoppers continue to look for leads in her disappearance.

The Sheriff’s current cold-case materials still identify Potrero as the location associated with the January 1, 1975 disappearance and continue to ask anyone with information to contact investigators or Crime Stoppers.

California’s Department of Justice also continues to maintain an active public missing-person entry for Harper, listing San Diego County Sheriff’s Department case 95-087100.

Publicly available records reviewed for this article do not reveal an announced arrest, identified suspect, recovery of Joyce’s remains, or resolution of the case.

Identifying Information

Joyce is described as a white woman with brown hair and brown eyes. She stood approximately 5 feet 3 inches tall and weighed approximately 120 pounds.

Her date of birth is listed by the California Department of Justice as December 9, 1945. Dental X-rays are listed as unavailable in the state’s record.

She may have used Joyce Gann or Vivian Ann Maddux.

Because more than 50 years have passed, investigators are necessarily looking backward. Information that seemed insignificant decades ago — a relationship, residence, vehicle, conversation, acquaintance or unexplained event — could potentially help reconstruct Joyce’s final known movements.

A Mother and Daughter Still Missing

Joyce Elizabeth Harper disappeared in 1975. Her daughter Kimberly Cozart disappeared in 1977. Their disappearances occurred approximately two years apart, and both cases went unreported for years before being formally reported on December 15, 1995.

What happened to Joyce remains unknown.

More than five decades after her disappearance, the San Diego County Sheriff’s Department continues to seek information about the case. Anyone who knew Joyce Harper, Joyce Gann or Vivian Ann Maddux — or who has information concerning her life in Potrero and disappearance in 1975 — could potentially possess information investigators have been seeking for decades.