Unsolved Case Files Canada
  • About Us
  • Contact
  • Files
     Trending  File Status  Cold Cases  Memorials  MMIWG  Photo Gallery  Reward Program  Submit a File  Submit a Tip 
  • Location
     Alberta  British Columbia  Manitoba  New Brunswick  Newfoundland  Northwest Territories  Nova Scotia  Nunavut  Ontario  Prince Edward Island  Quebec  Saskatchewan  Yukon Territory
  • Donate
Trending: Joanne Pedersen

Unsupported Browser! This website will offer limited functionality in this browser. We only support the recent versions of major browsers like Chrome, Edge, Firefox, Opera, Safari, and Brave.

UCF #104200218 | Updated: 2022-04-22

New information closes decades-old Muriel Mann Cold case


Muriel Mann
CLOSED

Muriel Mann

Update 2022

Because 38 years have passed and those involved have since died, police said they "will never be given the opportunity to validate our findings in court."

Pre-update

Saint John, New Brunswick — After 38 years, the gruesome murder of Rothesay nurse Muriel Mann has been solved with new information, clearing the name of Mann's former boyfriend 17 years after his own death, according to the Kennebecasis Regional Police Force.

On March 6, 1984, Mann's body was discovered in the freezer of her Hillhurst Drive home by two friends after they checked in her. At the time of the murder, Mann had been dating John Mavon, and according to his daughter Diane Heans, Mavon, who hadn't heard from Mann in a couple of days, was there at the home with a next-door neighbour when Mann's body was discovered.

ADVERTISEMENT

Despite public appeals, the Mann murder case grew cold over time. But on March 17, 2022 - a little over 38 years to the day of the murder - Heans says she received a call from the Kennebecasis Regional Police Force and was told her father, who had died in 2005, was no longer considered a suspect in Mann's 1984 murder.

Family and friends have known Mavon was innocent for decades, Heans says, but now, hopefully other people will believe it too. While police never formally accused Mavon of being a suspect, Heans says a "cloud" has followed her family's name for nearly 40 years.

When approached by the Telegraph-Journal with this information, the Kennebecasis Regional Police Force confirmed in a press release Wednesday, March 30, 2022 that Mavon is not a suspect in the homicide and the Mann case has been closed.

"As a result of new information received anonymously from the public, the KRPF Criminal Investigation Division recently re-opened this cold case, and now have new and updated information,” police said in a news release.

Detectives identified new suspects and, in response to a media inquiry, confirmed that John Mavon is not one of them.

ADVERTISEMENT

Police said they are "confident" that Mann had become aware of criminal activity by someone she knew and was murdered due to fear she might report it to police.

"Her children were never considered suspects and have been updated on these new findings," said police.

Because 38 years have passed and those involved have since died, police said they "will never be given the opportunity to validate our findings in court."

Memorials  New

Citing respect for everyone concerned, police said they will not provide more information on the case.

"Our investigation is now complete, and the file is closed."

  • Sabrina Polchies
  • James Brady and Absolom Halkett
  • Muriel Mann
  • Ambrose Small
  • Leanne Lori Benwell
  • Closed and Solved files cannot be updated.
Sandra Mlodzik

Sandra Mlodzik

Contributed by Sandra Mlodzik.
Brianne Wolgram
SPOTLIGHT
Brianne Wolgram

According to reports, Brianne Wolgram was in the company of three other young unidentified women. She was supposed to meet...

Make a Donation

We Need Your Support

Your donation helps us keep raising awareness of unsolved cases, unravelling the mysteries, and bringing justice.

Thank you for your generosity!

Make a Donation

Donate securely with Visa, Mastercard, Amex, Discover, JCB, Google Pay, Apple Pay, and more

Someone has to know something. To anyone out there who has information that could help, I only have one thing to say – come forward.

Malcolm Squires

The homicide of Lillian Morrell

Murders in Windsor
MOST-READ
Murders in Windsor

The 1980 murder of Kirk Knight; the 1982 murder of 31-year-old Marlene Sweet and her 7-year-old son Jason; the 2003 killings of 30-year-old Debilleanne "Dee Dee" Williamson and her son 5-year-old Brandon "Xavier" Rucker.
Windsor, Ontario

Subscribe

Subscribe to Unsolved Case Files Canada to receive new stories, news releases and updates


Please, if you are not receiving our mails in your Inbox, it is worth checking in your Spam or Junk mail folder. Unsubscribe at any time. Privacy

Brenda Lee Meyers
What Had happened To Brenda Lee Meyers? Was This An Accident?
  • Calgary, Alberta
Charlene Ward
Suspicious death of Charlene Ward
  • Portage la Prairie, Manitoba
John Hanna
Family Appeals For Help In 2009 Burnaby Slaying Of John Hanna
  • Burnaby, British Columbia
Casey Rose Bohun
Mysterious Disappearance Of 3-Year-Old Casey Rose Bohun
  • North Delta, British Columbia
More Files  
  • ©2026 Unsolved Case Files Canada. Some rights reserved. Not funded by and/or affiliated with a government agency.
  • Anyone with tips or information about unsolved cases is urged contact Crime Stoppers by calling 1-800-222-8477.

ucfiles.com

  • This Website does not accept responsibility for the adequacy or accuracy of the contributed Files, and assumes no responsibility for the content of external links.
  • Terms Of Service
  • Privacy Policy
  • Cookie Policy

My Account

  • Let's make today the time to uncover the truth and bring justice to those who have been forgotten.
  • Submit a File
  • Make a Donation
  • File Status

Connect

  • Do you have any questions or feedback about our website? Get in touch!
  • Send Us a Message
  • Live Support
  • Follow Us On X

Unsolved Case Files Canada

Proudly Canadian

Green Powered

GDPR and CPRA compliant.