Senior PSNI detective John Caldwell is suing the BBC and an MLA over comments made during a documentary about the investigation into the death of showjumper Katie Simpson.
The detective chief inspector, who suffered life-changing injuries in a dissident republican murder bid in 2023, is taking legal action over comments made by Alliance MLA Nuala McAllister on the BBC programme Spotlight.
The programme examined the police investigation into Ms Simpson’s death and whether some officers were initially reluctant to investigate the showjumper’s death as a potential crime.
During the documentary, Ms McAllister made comments about Mr Caldwell as head of a team within the PSNI.
Chief constable Jon Boutcher told the Policing Board earlier this month that the PSNI got things wrong in the initial stages of their inquiry, but robustly defended Mr Caldwell and said he was not facing any misconduct proceedings.
Ms Simpson, 21, who was from Tynan, Co Armagh, died in hospital almost a week after an incident in Gortnessy Meadows, Lettershandoney on August 3 2020.
Her murder was originally thought by police to have been a suicide.
It was not until the following year that Jonathan Creswell, the partner of Ms Simpson’s sister, was arrested on suspicion of murder.
The trial of Creswell, 36, over the rape and murder of Ms Simpson ended in April following his sudden death.
Creswell, who had a past conviction for abusing another woman, initially called the emergency services having claimed to have found Ms Simpson in the aftermath of the apparent suicide bid.
The legal team representing Mr Caldwell said that the Spotlight programme did raise “important concerns” about the PSNI investigation.
But it said the legal action being taken against the BBC and Ms McAllister, first reported by Sunday Life, aimed to contest “false allegations and inaccuracies” made about Mr Caldwell.
A legal representative for Ms McAllister said her comments were “intensely” researched and that she would be “strenuously” defending any proceedings issued.
WP Tweed and Co, representing Mr Caldwell, said in a statement to PA: “We have been consulted by DCI John Caldwell in relation to the BBC Spotlight programme into the death of Katie Simpson.
“Our client is deeply conscious of the tragic circumstances of Katie’s murder and that the PSNI Chief Constable has apologised for flaws and shortcomings in the initial investigation.
“The programme did raise very important concerns regarding the handling of the police investigation. However, our client is not the subject of any PSNI disciplinary process.
“Our client totally and categorically denies the false allegations and inaccuracies that seek to undermine his personal and professional reputation.
“Accordingly, we have been instructed to take appropriate action against Nuala McAllister MLA and the BBC.”
Kevin Winters of KRW Law said on behalf of Ms McAllister: “As a highly respected political representative she was approached to expose serious failings with the PSNI investigation into the killing of Katie Simpson.
“That included participating in a BBC Spotlight documentary.
“My client stands by her intensely researched commentary and will strenuously defend any proceedings issued challenging her contribution to that broadcast.”
The BBC has been contacted for comment.