Det Ch Insp Caldwell is one of the best-known detectives in the PSNI.

In 2023 he survived a dissident republican gun attack and was awarded the King’s Police Medal.

Ms McAllister said: “It has been alleged to me that it was DCI John Caldwell himself who put up the most resistance and acted in the way, I have been told, that was not befitting of a senior ranking officer.

Why did it take so long to look for Katie’s killer?

2 days ago

Jennifer O’Leary

Spotlight reporter, BBC News NI

A senior police officer has been accused of being resistant to investigating the death of showjumper Katie Simpson as a murder.

The 21-year-old died in hospital six days after an incident in a house in County Londonderry, in August 2020.

In the months after Katie’s death police treated her death as suicide before it was upgraded to a murder investigation.

The Police Service of Northern Ireland (PSNI) said Katie Simpson’s murder had left a family devastated and they continue to suffer unimaginably.

At the time of Katie’s death, Det Ch Insp John Caldwell led a major investigation team based at Maydown PSNI Station in Derry.

Alliance MLA Nuala McAllister, a member of the Policing Board, has told a BBC Spotlight investigation that a police officer from another team, who was trying to push for an investigation, was getting pushback.

“I am aware that there was an individual officer who did a lot of work and actually brought it forward to his superior to say: ‘This isn’t right here.’

“He met a lot of resistance, not from his superior but from within the team around the district in which Katie lived and where the death actually occurred,” she said.

“There was a police team in the PSNI who just didn’t want to know. I’ve been informed that it was DCI John Caldwell who led that team.”

Det Ch Insp Caldwell is one of the best-known detectives in the PSNI.

In 2023 he survived a dissident republican gun attack and was awarded the King’s Police Medal.

Ms McAllister said: “It has been alleged to me that it was DCI John Caldwell himself who put up the most resistance and acted in the way, I have been told, that was not befitting of a senior ranking officer. Why fight it? Why argue against it? Where was the harm in investigating it?”

Jonathan Creswell first met Katie and her family through working in horse stables near their home in Tynan, County Armagh.

He went on to have two children with Katie’s eldest sister, Christina.

It was a controlling relationship.“I didn’t know what he was like. He was a very cunning man.”

Creswell’s death meant he was not convicted of the rape and murder of Katie.

“I believe that ultimately by him taking his own life, that Jonathan Creswell did get away with murder,” said Ms McAllister.

If you have been affected by any of the issues raised in this article information about help and support is available on the BBC Action Line.

Spotlight’s Katie: Coerced and Killed is on BBC One NI Tuesday 23rd July at 21:00 and on BBC iPlayer.

Listen to Showjumper Murder: How a 999 lie threw police on BBC Sounds.