On July 29, 2009, Governor John Lynch signed into law HB 690, establishing for the first time in the state's history a Cold Case Unit assigned to work exclusively on unsolved murder cases. The New Hampshire Attorney General is the chief law enforcement officer for the state with exclusive jurisdiction over homicide cases. Most of the state's homicides are investigated by the New Hampshire State Police Major Crime Unit. However larger cities, such Concord, Dover, Keene, Manchester, Nashua, and Portsmouth, investigate homicides occurring within their jurisdictions.
The Cold Case Unit was organized in the Fall of 2009 to combine the experience of the Attorney General's Office, the Major Crime Unit, and a city detective. The Unit is staffed with a prosecutor and three detectives who will focus on reviewing unsolved homicides, unresolved suspicious deaths, and missing person cases in which foul play is suspected in the person's disappearance.
- Sergeant Matthew Koehler has over 19 years experience with the New Hampshire State Police and has been a member of the Major Crime Unit since 2011. He has worked on a multitude of active and historic homicides throughout his career. He was assigned to the Cold Case Unit in 2018, and since that time has been a contributing member to the successful case resolutions of the Cold Case Unit
- Detective Trooper James Soucy is a retired Manchester Police Department Captain with over 27 years of law enforcement experience. At the time of his retirement, he was Commander of the Investigative Division and a graduate of the prestigious FBI National Academy. He served as the Chief of Police for the Town of Kittery, Maine, a position he held for 2 years following his retirement. Throughout his career he's been involved in the investigation of numerous homicides, to include both current and cold cases, and is currently assigned as a part-time investigator with the New Hampshire State Police.
- Charles West is a retired New Hampshire State Police Lieutenant with over 30 years of law enforcement experience. At the time of his retirement, he commanded the State Police Major Crime Unit and is currently assigned as a part-time investigator with the Attorney General's Office.
- Tracey Flaherty joined the Major Crime Unit in March 2016 as its first Cold Case Analyst. Tracey has worked in the field of Intelligence Analysis for more than 20 years, beginning with the FBI in 1994. During Ms. Flaherty's analytical career she provided tactical and strategic investigative analysis for a variety of initiatives within the FBI. Throughout her career with the FBI, Ms. Flaherty has partnered with local, state and federal law enforcement agencies.
- Susan Morrell is a Senior Assistant Attorney General with over 30 years of prosecution experience. Susan has been assigned to the Homicide Unit of the Criminal Bureau for the past nine years. She was previously assigned to the Drug Prosecution Unit of the Criminal Bureau for 13 years. Her experience also includes serving as a Special Assistant United States Attorney in the District of New Hampshire, as an Assistant and Deputy Strafford County Attorney and as the Assistant and Acting City Attorney in Keene, New Hampshire.
- Joelle Donnelly Wiggin is an advocate with the New Hampshire Office of Victim and Witness Assistance. She has been assigned as the advocate for the Cold Case Unit since its start. As an advocate for the New Hampshire Office of Victim and Witness Assistance, she responds to homicide cases around the state to work with the families who have lost their loved one, as well as witnesses in the case. Ms. Donnelly Wiggin obtained her BS from the University of New Haven and recently achieved a Master Degree in Public Administration with a concentration in Criminal Justice from the University of North Carolina at Pembroke.
If members of the public have any information about any of the unsolved homicides in this state, they are encouraged to use the tip form to provide information to the investigators. The following is a list of cases under review by the Cold Case Unit.