When the family of Roger Leadbeater, a 74-year-old man stabbed to death while walking his dog yards from his home in Sheffield, went to lay flowers at the scene two days later, they were met with a horrifying sight.

“Nobody had cleaned the scene. It was the most barbaric thing I’ve ever seen,” said his niece Angela Hector. “There was blood everywhere. You could see the dog paw prints, the outline of his body. It was horrific. A dog walker stopped to talk to me, and his dog was licking Roger’s blood.”

Leadbeater’s family covered the blood with a large tarpaulin sheet, and sat there for more than five hours until South Yorkshire police arranged for it to be cleaned up.

The force has since apologised to the family over the issue, which was reportedly due to a mix-up between the police and the local council, and said protocols had been updated to ensure it did not happen again.

Hector, 55, and her family soon learned this was just one of a series of mistakes and miscommunications surrounding Leadbeater’s death on 9 August last year, and, with an inquest into his death due to start on Monday, say they want to know why things went so wrong.

He was killed by Emma Borowy, a 32-year-old woman with severe mental health issues who had absconded from a six-bed psychiatric intensive care ward in Bolton two days before the murder. They were told she stabbed Leadbeater more than 50 times, including through the eye and several times in the back as he attempted to crawl away.

Borowy was charged with murder and remanded in prison as she awaited trial, and later died in custody on 12 December.

As Leadbeater’s family began to piece together her history, and what had led her to be in the park near his home that evening, they uncovered a worrying series of events that suggested the risk to herself and others had not been properly assessed.

Borowy, who was diagnosed with schizophrenia and frequently talked about hearing voices, had absconded from hospital multiple times, sometimes from the ward itself by smashing windows and sometimes by running away while on supervised leave. She is known to have displayed threatening and aggressive behaviour towards staff, and refused medication.

On one occasion police brought her back to the hospital and she had allegedly spoken to officers about wanting to kill people and made references to a “bloodbath”, although she later denied this.

She ran away while on supervised leave on 4 August 2023, was returned to the hospital by police, and was again granted supervised leave three days later, on 7 August. She ran off while the healthcare assistant who was monitoring her was buying food at a shop and travelled to visit a friend in Sheffield.

She went on to kill Leadbeater on the night of 9 August, with CCTV footage showing her pacing the area and hiding in bushes shortly before the attack.

Hector said: “Roger was just a nice, hard-working guy. He wouldn’t have harmed anybody, and what he endured that night and how she killed him – that could have been prevented. It was a domino effect among different services – if they’d have done this, if they’d have done that.

“It seems like her treatment and care was very poor.

“She should never have been granted leave again on 7 August. We aren’t even asking for new policies to be put in place; we just want them to follow the ones they already have. They’re there for a reason – to protect the individual and protect others from harm – but they just didn’t follow them.”

Leadbeater was well known in the suburb of Westfield where he lived. He drove a minibus transporting children with special needs to and from school, loved caring for his rescue dogs and was obsessed with gadgets.

“He never married, he didn’t have any children – he was too busy with our lot,” said Hector fondly, as she described how he loved spending time with his nieces and nephew, their children and grandchildren. “We are a big family. He was always coming over.”

Lindsey Hammond, 36, his great-niece, said: “We thought he had a bit of a secluded life – that it was just us – and actually we found out he knew everybody. He talked to everybody and everyone’s got a story about him.”

The family are being supported by Julian Hendy, who set up the charity Hundred Families after his father was killed by a man with psychosis, who was known to mental health services, in 2007.

“It’s a whole catalogue of errors, this story,” he said. “There are a lot of questions that need answered. There are clear issues with risk assessments, monitoring medication and passing on information, and these issues keep happening again and again.

“This is not about general people with a mental health problem; this is a small number of people who are known to be dangerous to need more assertive care and treatment.”

Hector said: “This has completely changed us as a family – it has changed our outlook on things, the way we look at services, the way we look at everything.

“People said Roger was just in the wrong place at the wrong time. No, he was in the right place at the right time, walking his dog where he’d always walked his dog for years, and he shouldn’t have had to encounter what he did that night.

“In Roger’s name we want justice, whatever that looks like in this case – there were mistakes and they can’t deny that.”

Dr Arasu Kuppuswamy, the chief medical officer at Greater Manchester mental health NHS foundation trust said: “Our thoughts and sympathies remain with Roger Leadbeater’s family following his tragic death. It would be inappropriate for us to comment further until the coroner’s inquest has concluded.”

A spokesperson for Greater Manchester police said: “We understand the impact of Roger’s death on his family and loved ones. It is important for all involved that they get the answers they deserve at his upcoming inquest.

“We know there will be matters for us and other partners agencies to be rightly held to account for. We are committed to ensuring that we do all we can to support the coroner as part of a full and fearless inquest into Roger’s death.”

A spokesperson for South Yorkshire police said: “We have been in ongoing contact with Roger’s family since his tragic death and we will continue to support them throughout the inquest process.”