However, jurors were prevented from deciding whether the failings contributed to Gracie Spinks' death.

The 10 members of the jury, who wore pink and purple wristbands in Ms Spinks' memory, concluded the 23-year-old was unlawfully killed.

She was last seen alive by her mother on 18 June 2021 when she left the family home in Chesterfield to drive a few miles to Blue Lodge Farm stables in Duckmanton.

Half an hour later, she was found unconscious at the stables with a fatal stab wound to the neck.

The body of 35-year-old Michael Sellers, who she first met in 2020 when he was her former supervisor at a warehouse where she had a temporary job, was discovered in a nearby field a few hours later.

He had left a note saying he "could not deal with all of her lies".

During the inquest, a coroner said this was one of "various pieces of evidence" that Sellers had killed Ms Spinks and then taken his own life.

Months before her death, Ms Spinks had reported Sellers to their employer and the police for stalking after he became infatuated with her and turned up at the stables in Derbyshire, where the keen rider kept her horse.

The inquest concluded police should have conducted a risk assessment when a stalking allegation was reported to them in February 2021, the force should have referred the case to the Public Protection Unit and employment records should have been sought.

Police dismissed a bag of weapons which was later linked to Sellers - found near to where Ms Spinks was killed.

The inquest found that there should have been an investigation into the bag, including house-to-house enquiries and an examination of a receipt found in the bag.

Returning their conclusion on Thursday, in which he referred to Sellers as "the supervisor", the jury foreman said: "Derbyshire Constabulary had admitted the following serious failings.

"However, it could not be concluded that these failings contributed to Gracie's death on June 18 2021.

"It was the supervisor that killed Gracie."

Following the deaths, the Independent Office for Police Conduct (IOPC) investigated five Derbyshire Police officers for misconduct.

Gracie was 'loved by everybody that met her'

Richard Spinks, Gracie's father, told Sky News that his daughter was "loved by everybody that met her".

"She was one of those type of people that you thought, 'I'd like to be with her again'. 'I'd like to meet her again'.

"Just a lovely young girl at the start of her life that was just cut too short."

This breaking news story is being updated and more details will be published shortly.

Please refresh the page for the fullest version.

You can receive breaking news alerts on a smartphone or tablet via the Sky News app. You can also follow @SkyNews on X or subscribe to our YouTube channel to keep up with the latest news.