Police in Northern Ireland have apologised to the family of murdered showjumper Katie Simpson after a watchdog found their initial investigation was flawed.

The Police Ombudsman investigation concluded it had “failed” Ms Simpson’s family and criticised a “lack of investigative mindset”.

The 21-year-old from Tynan, Co Armagh, died in Altnagelvin Area Hospital almost a week after an incident in Gortnessy Meadows, Lettershandoney, on August 3 2020.

Police originally thought she had taken her own life.

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, for the murder of Ms Simpson ended in April following his sudden death.

Ms Simpson’s mother Noeleen Mullan said the family felt “empty” and that nothing had been achieved after reading the report.

She has called for more accountability among the senior ranks of police.

However she also paid tribute to the work of a senior detective and members of the public who came forward for the case being brought against Creswell.

PSNI Chief Constable Jon Boutcher previously met with the Simpson family, and is understood to have offered to meet them again following the Ombudsman’s report.

On Tuesday, Assistant Chief Constable Constable Davy Beck apologised on behalf of the service following the release of the report.

During a press conference at PSNI headquarters in Belfast, he expressed his sympathies to Ms Simpson’s family and friends, and said he acknowledged there were “shortcomings in various stages of the investigation into Katie’s death”.

“I unreservedly apologise for this,” he said.

The Ombudsman’s investigation concluded that the police investigation was hindered by the misleading working assumption adopted by a number of officers that Ms Simpson’s injuries were self-inflicted.

They criticised a “lack of investigative mindset” taking into account police had received intelligence that Ms Simpson may have been the victim of controlling behaviours, that the attempted suicide was suspicious, that she had not fallen from a horse, and that medical staff had also expressed concerns about the circumstances of her injuries.

Police Ombudsman chief executive Hugh Hume said although this intelligence was viewed and logged by police, it “did not change the direction of the police investigation”.

“There appeared to be a general lack of an investigative mindset which contributed to shortcomings,” he said.

The investigation found there were no effective searches carried out at Ms Simpson’s address and that no supervisory officer attended the house at the initial stages of the investigation.

Among the other investigative failings identified by the Police Ombudsman was the lack of consideration given to gathering potential physical evidence from Ms Simpson herself, including blood samples and photographs of her injuries, despite police being aware at an early stage that she was unlikely to survive.

The Police Ombudsman investigation identified breaches of the Police Service of Northern Ireland (PSNI) Code of Ethics in respect of professional duty, the conduct of police investigations and the duty of supervisors.

As a result, disciplinary recommendations were made to the PSNI in respect of six police officers. No action was taken against three officers, two of whom had retired and one for whom no misconduct was proven.

One police officer received a written warning, another received action aimed at improving performance and one received management advice.

Three recommendations have been made to the PSNI.

The family’s solicitor Kevin Winters described the Ombudsman’s findings as a “stepping stone on what’s still a long, tortuous road to justice for the Simpson family”.

“Today’s findings help provide much-needed answers but equally there are unresolved issues arising from new complaints, one of which involves a serving member of police,” he said.

“As part of the accountability process the family feels strongly about taking legal action and a number of family members have indicated that they want to do that because ultimately they were already deeply traumatised by what happened to Katie and retraumatised by the recorded policy failings, and there has to be accountability for that.”

It is understood the family has submitted further complaints to the Police Ombudsman.

An inquest is also due to be held to examine the circumstances of the death of Ms Simpson.

At a brief hearing at Laganside Courthouse on Tuesday, coroner Joe McCrisken was updated on preparations for the inquest, including the process of disclosure of material by the PSNI and Police Ombudsman.

The next review hearing will be held on January 21.