A chief constable has apologised to the families of a taxi driver who shot three relatives dead then killed himself, as a coroner said the tragedy could have been avoided.
Shortcomings in Durham Police's Firearms Licensing Unit, including a focus on administration rather than investigating applicants, have been highlighted during an inquest into the deaths of Michael Atherton, 42, his partner Susan McGoldrick, 47, her sister Alison Turnbull, 44, and Alison's daughter Tanya, 24.
Atherton blasted the women in the back following a row at his home in Horden, near Peterlee, on New Year's Day 2012, then shot himself in the head.
The weapon, a Hatson Escort Magnum semi-automatic shotgun, was one of six he was entitled to own despite a history of drunken domestic violence, and threatening to "blow his head off" in 2008. On that occasion police removed his weapons but returned them a few weeks later with a warning to behave responsibly in future.
Speaking to bereaved relatives at the inquest in Crook, Chief Constable Michael Barton said: "I apologise on behalf of the organisation that your family and friends have been put through what nobody would want to go through."
Coroner Andrew Tweddle reached verdicts that the women were unlawfully killed and that Atherton, a keen shooter, took his own life.
The four-day hearing has concentrated on failings within the licensing unit which have left Mr Tweddle concerned they may exist in other forces. Mr Tweddle will write to the Home Office calling for "root and branch" changes and possibly legislation surrounding how police license shotguns.
In his judgment, the coroner said: "In my opinion, these deaths were avoidable. The systemic shortcomings highlighted by me today lead me to conclude that, on a balance of probabilities, the four deceased would not have died when they did in the manner in which they did had there been robust, clear and accountable procedures in place."
The coroner accepted that no one in the Firearms Licensing Unit acted in bad faith, but said "the system in place at that time was not fit for purpose so that the decision-making process was flawed". He said staff gave "undue significance" to the possibility of losing an appeal if they revoked or refused a licence.
The Independent Police Complaints Commission has investigated Durham's failings and has made recommendations so that the same mistakes would not be repeated.