Margaret Mary Kilcoyne

Above: Kilcoyne, circa 1980


Vital Statistics at Time of Disappearance

  • Missing Since: January 26, 1980 from Nantucket, Massachusetts
  • Classification: Endangered Missing
  • Age: 50 years old
  • Height and Weight: 5'0, 140 pounds
  • Distinguishing Characteristics: Caucasian female. Red hair, blue eyes. Kilcoyne's nickname is Peg. She wears horn-rimmed eyeglasses.
  • Clothing/Jewelry Description: Possibly a yellow sweater.
  • Medical Conditions: Kilcoyne was experiencing severe mental stress at the time of her disappearance and may have been suffering from an episode of depression or mania.
  • Bar

    Details of Disappearance

    Kilcoyne was last seen at her secluded vacation home in Nantucket, Massachusetts on January 26, 1980. She went to bed at 10:00 or 10:30 p.m. Just before 7:00 a.m. the next day, when her brother came to wake her up for church as she had requested, she was gone. Her winter boots were on the floor and her only coat was hanging in the closet. Her bicycle and car were still in the garage. Kilcoyne has never been heard from again. Temperatures on the night she disappeared were well below zero degrees, and in subsequent days the weather was so cold that one of the search planes crashed because its carburetor froze.

    Kilcoyne was a cardiologist doing research at Columbia University, looking for treatments for hypertension. Just before her disappearance, she told her loved ones she had made a dramatic breakthrough in her medical research and might win a Nobel Prize. Her colleagues stated they had in fact made a breakthrough, but that it wasn't as important a discovery as Kilcoyne thought it was. She did not leave a note explaining her actions, and she didn't tell anyone of any plans to leave. The day before she went missing, she bought $650 in groceries and $250 worth of liquor. All the grocery items were purchased in multiples of three. She told people at the grocery store that she was going to hold a party and press conference to announce her research findings. However, she didn't tell her family about any party, and she hadn't contacted the media or made any other arrangements to prepare for such an event.

    Several days after her disappearance, searchers found Kilcoyne's passport, checkbook, summer sandals, and a wallet with $100 inside stacked neatly in a clearing near her home. The items were in a location that had been previously searched, and nothing had been found then. A clean brown long-sleeved blouse, believed to be Kilcoyne's, was found inside-out and rolled up under some brush about 150 yards away. Authorities said the blouse had been deliberately placed there and whoever did it would have to crawl through the brush on their hands and knees.

    Kilcoyne's brother stated she was stressed over her work and he had been concerned for her mental well-being, which is why he came to her summer house the day before her disappearance. He decided to go see her after a phone conversation with her where Kilcoyne spoke very rapidly, was elated about her medical discovery, and also said she suspected she was being spied on at work. Her brother scheduled an appointment for her to see a psychiatrist for January 27, the day after her disappearance.

    One prominent theory is that Kilcoyne killed herself, either intentionally or accidentally while in a delusional state, by walking into the ocean. Her family believes this is what happened, but some investigators in her case think she is alive and left of her own accord. She was declared legally dead in 1989, leaving behind a $200,000 estate. Foul play is not suspected in her case.

    Kilcoyne was born in Worcester, Massachusetts. She graduated from Boston Children's Hospital School of Nursing in 1951 and went on to obtain a bachelor's degree from Boston University and a medical degree in 1964 from the University of Vermont. Her case remains unsolved.


    Investigating Agency
    If you have any information concerning this case, please contact:
    Nantucket Police Department


    Source Information
    The Doe Network
    The Worcester Telegram and Gazette
    The Boston Globe
    New York Magazine


    Updated 2 times since October 12, 2004.

    Last updated February 25, 2014; middle name added.

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