The Disappearance of Joyce Elizabeth Harper, 1975

According to both the Doe Network and Charley Project, as well as CA DOJ, Joyce Elizabeth Harper was born on December 9, 1945; based off of this birth date, she would have been about 29-30 years old when she disappeared. However, her age at time of disappearance across both of those sources, plus NamUs is inconsistent: she is described as having been 29 (Charley Project), 31 (DN), or 32 (NamUs). Her date of disappearance, January 1, 1975, is approximated; she was last seen sometime in 1975. She lived in Potrero, San Diego County, CA at the time. 

Photo from NamUs.

Very few details are available in Joyce's case. She is considered missing under suspicious circumstances, and is listed as Endangered Missing according to Doe Network and Charley Project.

Joyce is a white female. She was 5'3 and 120 lbs at the time of her disappearance. She has brown eyes as well as brown hair that was shorter than collar length at the time. Joyce may use the last name Gann, and/or the alias Vivian Ann Maddux.

Joyce had at least two daughters, one of which, Kimberly Cozart, was reportedly born on July 7, 1962; however, there are some discrepancies regarding her age, as she is variously listed as being 14 or 15 years old in February 1977. Either way, Joyce would have been 16 to 20 years old when Kimberly was born; specifically, using the birth dates given for each, Joyce may have been about 16 years 7 months old when she gave birth to Kimberly.

Both Joyce and Kimberly were reported missing by Joyce's other daughter on December 15, 1995. Kimberly went missing sometime in February 1977, and it is unknown whether her disappearance is related to her mother's.

Joyce has ten rule-outs on NamUs, two of which were found in CA (in 2006 and 2013), while the other eight were found in VA. Her DNA is available for comparison, while her dentals — including dental x-rays — and fingerprints are not.

Anyone with information regarding Joyce should contact the SD County Sheriff's Department at (858) 974-2143. The agency case number is 95-087100. Her NamUs case, #MP18020, was created on November 6, 2012 and last updated on May 9, 2023.

Furthermore, according to the CA DOJ's missing persons database, "If you think you know the whereabouts of any person, BEFORE TAKING ANY ACTION, please contact the law enforcement agency listed in the record, or the California Department of Justice at 1-800-222-FIND (24 hour nationwide toll-free Hotline) or (916) 210-3119, or email us [CA DOJ] at missing.persons@doj.ca.gov." According to the same site, individuals seeking to contact CA DOJ regarding a missing person can use the email form here.

Sources

NamUs 

Doe Network 

Charley Project  

CA DOJ

San Diego County Sheriff's Office cold cases

WebSleuths 

Reddit post with comments 

List of CA cases, ZK Ciphers forum 

Note: While this write-up was originally published on July 11, 2025, I regularly revisit cases, fix any typos or formatting errors, check for updates, hyperlink new posts, ensure that I have exhausted all sources, etc., and then make note of when I last did so, no matter how minor. When edits are extensive, I re-post the write-up entirely. This post was last updated on October 26, 2025.