The family of showjumper Katie Simpson is to sue the PSNI over its botched investigation into her suspected murder.
The 21-year-old died in hospital six days after she was assaulted at her home near Derry in August 2020.
Initially treated by police as a suicide, her death was later upgraded to murder.
Jonathan Creswell, a former jockey, took his own life after the first day of his trial for murder and rape in April.
Prosecutors had argued that Cresswell attempted to cover-up the suspected murder of Ms Simpson by claiming she had tried to take her own life.
The case has been shrouded in controversy over the PSNI’s approach during the early stages of their investigation.
In total four separate reports were made to police urging them to investigate the case firstly as an assault and murder after her death.
Medical staff also brought up concerns about the nature of the injuries suffered by Ms Simpson.
Police were also aware that Creswell served a six month prison sentence for strangling and threatening a former girlfriend.
PSNI Chief Constable Jon Boutcher has already acknowledged shortcomings in the initial stages of the investigation.
Solicitor Kevin Winters, of KRW Law, said he has now been instructed by a “number of the close family relatives”, including Ms Simpson’s parents, to take legal action “over police failings in the initial stages of the investigation”.
“Many of them were badly retraumatised over the outworkings of the seriously flawed suicide theory adopted by investigators,” he said.
“They will sue the PSNI for negligence.”
Concerns have also been raised about delays by the Police Ombudsman in publishing a report into Ms Simpson’s death.
Mr Winters said the decision by Ms Simpson’s family to take legal action wasn’t easily reached.
“The decision wasn’t made lightly coming as it does in advance of a PONI (Police Ombudsman) report into PSNI handling of the case,” he said.
“The PONI (Police Ombudsman) findings are expected to be critical of the early stages of the inquiry.”
A spokeswoman for the PSNI said: “The Police Service of Northern Ireland’s response will remain the same in relation to any queries surrounding legal matters concerning this case.
“We will not be commenting while legal and other proceedings are ongoing.”
