In the sittingroom of her home in Dunloy, Co Antrim, a framed photograph of Shannon McQuillan smiles down from the mantelpiece.

“She wanted to be a human rights lawyer,” says Paul McQuillan, looking up at the picture of his daughter. “She hated injustice, and she was going to try and correct things.

“She wanted to provide justice for people that were being treated the same way she ended up being treated.”

A 19-year-old law student at Ulster University, Shannon had been on a night out with her boyfriend, Owen McFerran, when she was knocked down and killed in the early hours of January 20th, 2018, after being left alone at a bus shelter in Magherafelt, Co Derry, by Police Service of Northern Ireland (PSNI) officers and a Northern Ireland Ambulance Service (NIAS) paramedic and trainee.

Owen, then 21, suffered life-changing injuries.

Earlier this month, following an investigation, the Police Ombudsman for Northern Ireland concluded there had been “multiple breaches in the duty of care” offered to Shannon and Owen, and that the PSNI response was “wholly inadequate”.

This included failing to “complete even the most basic checks” in relation to them, to recognise the vulnerability and danger of leaving them alone beside a road, and to safeguard their welfare.

“More should have been done in this case to protect the extremely vulnerable young woman and man from harm,” said the Police Ombudsman’s chief executive, Hugh Hume.

“You’ve been treated as if you don’t count,” says Paul, “because Shannon didn’t count [to them]. She may not have counted to them, but she definitely counted to us.”

Shannon was one of four children; first came a son, then three girls in three years, each born a year apart, with Shannon in the middle.

“They were very close,” says Paul. “Shannon was an independent young girl, she liked doing her own thing, and was very easy to get on with, very easy-going.”

She was into make-up, had “the most beautiful ginger hair” and was funny – he laughs, remembering “some of the one-liners she used to come out with”.

“Our conversations were always having a wee joke at each other, because each one thought they were as quick-witted as the other.”

Shannon shared her mother Collette’s passion for heavy metal and rock music, and was “a really caring person,” he emphasises. “No matter what lengths she had to go to care for somebody or something, she would go to those lengths.”

This included saving a kitten and bringing home an injured duck; they still have her pet tortoise, Arthur.

“She was a nice girl, and a good daughter,” says Paul.

That evening, Shannon and Owen were going out to a nightclub. According to the Police Ombudsman, they first came into contact with the PSNI and ambulance service at 2am, in a car park in Magherafelt. Shannon had fallen “a number of times”, hit her head and was unconscious, and had visible injuries to her leg. Subsequent tests showed both had high levels of alcohol in their blood.

A decision was made to take them to hospital, but the ambulance personnel called police back to the car park after Shannon’s behaviour became “erratic”.

Police agreed to follow the ambulance, but shortly before 3am, it pulled into a bus layby on the Moneynick Road in Magherfelt and called again for police assistance.

Following a discussion between the emergency services, Shannon and Owen got out of the ambulance “and were left, alone, at a bus shelter”.

Collette had already received a call from the police, asking her to go and meet Shannon and Owen at the hospital. Then, at about 3.30am, Shannon phoned.

“I said, ‘Where are you at?’. They hadn’t a clue where they were … Owen said: ‘The police put us out’.”

The ombudsman stated that “at 3.38am the police received the first of three phone calls about two people walking in the middle of the Moneynick Road.

“Two minutes later, a motorist informed police that he had collided with two people on the same road.” Shannon died at the scene.

Owen had told Collette he thought they had been left at Logan’s Fashions, a well-known shop near Dunloy but about 48km away from their actual location. “I got in the car and went over to Logan’s Fashions and there was no Shannon and Owen.

“I kept trying to contact them, it went to voicemail, so I went back home and kept trying to phone and phone.

“Then at five o’clock in the morning I got a call from a policeman that he was coming to see me. So I knew.”

Following the tragedy, one of the three police officers who attended the ambulance received a written warning for gross misconduct, and another was dismissed from the PSNI. This dismissal was set aside on appeal, but the officer died before a hearing could take place.

A third officer was disciplined for breaching the PSNI’s code of ethics.

The ombudsman’s office submitted a file to the North’s Public Prosecution Service (PPS) for the potential offences of gross negligence, manslaughter and misconduct in public office. The PPS directed no prosecutions.

A separate PSNI investigation was carried out into the conduct of ambulance service staff and a police file was submitted to the PPS, but no criminal charges were brought.

As a result of the “wholly inadequate” communication between police officers and ambulance staff, such as failures to pass on key information – including that Shannon had been unconscious, and contradictory accounts of what happened – the ombudsman has recommended a new policy, currently under development, for the PSNI and NIAS for dealing with people who are intoxicated and refuse medical treatment.

“This is definitely positive, if it saves somebody else,” says Paul.

Yet 7½ years on from their daughter’s death, he and Collette are still searching for answers.

“They should have been sacked for the way they behaved that night,” says Paul. “They cost my daughter’s life, and they’re not even man enough to stand up and admit their mistakes.”

Collette has taken a civil case against PSNI Chief Constable Jon Boutcher and the NIAS. In the wake of the Police Ombudsman’s report, they are calling for the PPS to look again at prosecutions, and for a similar investigation to be conducted into the actions of the NIAS.

They have many questions. Why was one of the police officers involved subsequently promoted twice? Why was a patient report form destroyed? Why could the police not have phoned to say they were leaving them in the layby?

“Why did one of the cops say you come from a republican family … it’s trying to discredit the family,” says Paul.

“It’s been lies, and cover-ups, the way they’ve tried to portray it. It just goes to show you, the whole establishment, circles the wagons, the truth, never [comes out].”

“Where was the compassion for Shannon?” asks Collette. “They didn’t take into account the head injury that may have caused that erratic behaviour.

“The police were totally unprofessional, they did not do what they should have done. They failed Shannon in every way.

“Are we just left – that’s it, accept it? No, I’ll never accept it. There is an injustice and I will fight for justice for my wain [child].”

The McQuillans’ criticisms were put to the PSNI and the NIAS, and they were offered the opportunity to respond.

In a statement, the PSNI said it had nothing to add to its comments following the Police Ombudsman’s findings, when Assistant Chief Constable Anthony McNally said: “Our thoughts are very much with everyone who has been affected by this awful and tragic incident.

“We accept that more could and should have been done by police to prevent the circumstances that preceded Shannon’s death and Owen’s injuries,” he said. “For that we are truly sorry.

“We will now take further time to carefully consider the ombudsman’s report and assure ourselves that lessons have been learned particularly around the identification of vulnerability, risk assessment and adherence to service policy.”

The NIAS said it was “unable to provide any comment on account of ongoing legal proceedings”.

Collette and Paul still talk to their daughter every day. For Collette, their conversations are on the sofa at home. “She’d be like me, wee cup of tea and a wee smoke and oh, we’d put the world to rights about homelessness and how can this be, and that’s not right.”

She keeps in regular contact with Owen. “He was always part of our family, and he always will be.”

Paul goes to Shannon’s grave. It is a few minutes’ drive away, across the road from the chapel and with a view of the village and the green hills beyond. As he stands there, he thinks, “You shouldn’t be in there, pet.”