In 2022, the case against three men accused of murdering Upper Hutt woman Lois Tolley fell over after a judge ruled evidence - including a confession - had been improperly obtained, and was inadmissible in court.
Part of the reason was the use of a mysterious interviewing technique called the Complex Investigation Phased Engagement Model, or CIPEM.
Now a international expert who validated the interviewing technique says her conclusions were wrong and it doesn't meet international standards for evidence-gathering.
Journalist Mike White has been investigating the issue for Stuff and speaks to Nights about the latest developments.
Lois Tolley was killed in 2016. Charges were dropped against her three alleged assailants in late 2021. Photo: RNZ / Supplied / NZ Police
