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Theresa Marcoux death by force case profile photo

Theresa Marcoux

Case from West Springfield, MA dated Nov 19, 1978

Victim Details

Theresa Marcoux

Female

White / Caucasian

West Springfield

MA

1978-11-19

18

Theresa

Marcoux

07/03/2026

Case Description

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In the pre-dawn hours of November 19, 1978, the quiet of a rest area off Route 5 in West Springfield, Massachusetts was shattered by an act of brutal violence that would leave a community shaken and a mystery unsolved for decades. It was there that a patrolling officer discovered a green Dodge pickup truck with a damaged window and blood in and around it. The grim discovery led the officer over a nearby guardrail where the bodies of 18-year-old white female Theresa Marcoux and 20-year-old Mark H ...
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Links to Additional Sources (9)

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  • reddit: Reddit - UnsolvedMurders - Today is 42-year anniversary of the murders of Theresa Marcoux and Mark Harnish
  • Decades-old fingerprint leads to arrest in 1978 Massachusetts ...
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    Forum Posts (1)

    I’ve been following the case of Theresa Marcoux and Mark Harnish for a while, and can't seem to sh... ...Read More
    02/16/2023
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