Seif Benkailly Mahssen

Date of Birth*: May 23, 1957
Birthplace: Weirton, West Virginia, United States
Age at the Time: 0 (Infant), 5 Months
Age Group: Infant
Biological Sex: Male
Hair: Black, Brunette, Dark Hair
Eyes: Brown
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Ethnicity: Caucasian or White, Middle Eastern, Mixed Race
Nationality: United States, Yemen
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*If the date says January 1, this is often just a placeholder for an unknown specific date. It usually means “sometime that year”.

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Date of the Disappearance*: November 1, 1957

Description: Seif’s parents, Mary Jane Campbell and Kailly Mahssen, married on February 18, 1957, in Weirton, West Virginia. Weirton was known in the 1950s for its steel industry, particularly the Weirton Steel Mill, where Seif’s father claimed to work. The family’s residence was in this community, which had a population of around 24,000 at the time, characterized by working-class neighborhoods and immigrant populations, including some from the Middle East due to labor demands.

Kailly, a Yemeni immigrant, claimed employment at the Weirton Steel Mill, though subsequent investigations found no records confirming this. Seif was born three months later on May 23, 1957. On November 1, 1957 (some sources cite 1958, but this appears to be an error based on majority documentation), Kailly informed Mary Jane that he was taking their infant son on a temporary trip to Yemen to visit family. The planned duration varied in reports: some say two weeks, others 30 days. Kailly and Seif departed, but neither returned as promised, and no communication followed.

When Mary Jane attempted to locate them, she discovered several red flags: no employment records for Kailly at the steel mill, no immigration documents under his name, and suspicions that “Kailly Mahssen” was an alias (possibly a variation of Khalid Hassen or similar). Authorities classified the case as a non-custodial family abduction, where a parent removes a child without legal custody rights or consent, often across international borders. Local police in Weirton and the West Virginia State Police initiated searches, but the era’s lack of modern tools hindered progress. No evidence of foul play beyond the abduction was found, but the sudden disappearance left the family devastated.

In April 2008, a notice appeared in the Yemen Times seeking information about Seif, placed by relatives in the United States. The notice stated that Seif had been taken to Yemen by Kailly in 1958 (note the issue with the date). It suggested that Kailly may have later returned to the United States without Seif, or possibly resettled in a different state. The notice named several individuals believed to be possible relatives in Yemen (Hamid Saleh, Hassanain Chaibi, Amed Ali, and Hassen Ali) and noted that Seif has seven half-siblings in the United States who were hoping to make contact.

Despite the 2009 report, no official confirmation from law enforcement or government authorities has been made public.

Multiple Victims?: No

Rumored or Actual Sightings: A major development occurred on December 22, 2009, when the Charley Project, a U.S.-based missing persons database, received an email from a family member stating that Seif had been located alive and well in Yemen. Following this report, his profile appears to have been removed from some missing-person listings, although the National Missing and Unidentified Persons System (NamUs) continues to classify the case as open.

*If the date says January 1, this is often just a placeholder for an unknown specific date. It usually means “sometime that year”.

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Suspected Homicide?: Yes

Multiple Victims?: No

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*If the date says January 1, this is often just a placeholder for an unknown specific date. It usually means “sometime that year”.

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Description: The child’s father had lied about his name and workplace but is believed to have originally come from Yemen. Claimed to be Kailly Mahssen”, but this was an alias (possibly a variation of Khalid Hassen). May have been connected to Hamid Saleh, Hassanain Chaibi, Amed Ali, and Hassen Ali in Yemen.