New Hampshire Cold Case Unit Highlights Two Unsolved Homicide Cases

October 12, 2025

By: Scanner Alerts Media Group

New Hampshire authorities are renewing attention on two unsolved homicide cases—one in Manchester from 2010 and another in Portsmouth linked to a deadly 1986 arson—urging anyone with information to come forward.

Manchester: Death of Lynne Brennan (2010)

• Victim: Lynne Brennan, 53

• Last seen: Monday, October 4, 2010, at Bunny’s Superette, 75 Webster Street, Manchester, around 3:29 p.m.

• Discovered: Monday, October 11, 2010, during a welfare check at 267 North River Road; she had not been seen for about a week.

• Case status: Investigators believe Brennan was killed sometime before Sunday, October 10. The case remains an unsolved homicide.

Portsmouth: Fatal Arson at 314 Islington Street (1986–1987)

• Victims:

  
  

  • Joseph Poulin, 29

  • Terry Giles, 24

  • Linda Plummer, 39 (succumbed to injuries on March 30, 1987, at Massachusetts General Hospital)

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• Incident: A fire discovered around 3:25 a.m. on Saturday, October 11, 1986, at 314 Islington Street.

• Cause: Determined to be arson.

• Case status: Unsolved homicides.

How to Help

If you have any information that could assist investigators in either case, please contact the New Hampshire Cold Case Unit at coldcaseunit@dos.nh.gov.

Credit: New Hampshire Department of Justice – Cold Case Unit