[caption id="attachment_68364" align="aligncenter" width="600" caption="Hazel Stewart."]
Northern Ireland's Police Ombudsman has found that the original investigation into a double murder 20 years ago was "deeply flawed."
Two senior RUC officers who investigated the deaths of Trevor Buchanan and Lesley Howell overlooked vital clues the report says.
Both Buchanan and Howell were killed by dentist, Colin Howell, and his then lover, Hazel Stewart. Their spouses' bodies were discovered in a fume-filled car in a garage in Castlerock, County Derry on May 19, 1991.
At the time, police concluded that the deaths were suicides. Yet injuries to Mr. Buchanan's face were not documented and inconsistencies and lies told by Colin Howell and Hazel Stewart were not challenged, the report found.
It also found that forensic evidence was not gathered, information given to the police by a witness who said Howell was giving his wife medication, had financial troubles, and had previously dropped a live electrical cable into her bath, was ignored.
In a statement, the Police Service of Northern Ireland said they accepted the reports findings.
The case into the two deaths was reopened in 2009 after Colin Howell walked into a police station and confessed that he had killed his wife, Lesley, and his lover's husband, Trevor Buchanan.
Both Howell and Hazel Stewart are currently both in jail, convicted of the double murders.
On Tuesday the ombudsman's report found that 20 years ago two senior police officers rigidly stuck to the suicide pact theory.
The report said that no fingerprints were taken at the scene and key pieces of evidence were not forensically examined.
It added that "peculiarities" at the scene that suggested foul play were not fully investigated. Trevor Buchanan's leg was hanging out of the car door and the driver's window was open.
The police ombudsman concluded that there was "a lack of open-mindedness" and "a clear absence of leadership."
"Both families were failed by an investigation that was deeply flawed," the report said.
