Hours before Katie Madden took her own life, she had a tense phone call with her former partner Jonathon Russell. Russell was on bail after allegedly assaulting Madden – he was banned from contacting her – but the conversation took place nevertheless.

There was a witness to the call who gave evidence to the inquest into Madden’s death. Mason Jones, a friend of Madden’s, said Russell was “vile” and “abusive”. Although Jones said he could not remember the exact words Russell used, he said: “I recall Jon saying at least once that he was in control of the town and would end her life if she didn’t do it herself.”

In evidence, Russell denied saying this, but he did admit he had encouraged Madden to kill herself before this.

In the days leading up to Madden’s death, her mother, Bernadette Sutton, had told police and social services that she was concerned about the threat Russell posed to her daughter. “By this point, I thought he would kill her or she would take her own life,” Sutton said, in a statement.

Nigel Parsley, the coroner, concluded that Madden died by suicide while the balance of her mind was disturbed, but he also cited her relationship with Russell, with whom she had two children, as a contributory factor.

“Kate’s toxic relationship, in conjunction with Kate’s known mental health conditions, affected her state of mind and therefore contributed to her death,” he said.

The circumstances surrounding Madden’s death are no doubt tragic, but they are also an example of an increasingly controversial area of UK justice, one which has been described as a blind spot in the law’s ability to see the growing numbers of suicides among domestic abuse victims as something more: evidence of potential crimes.

Analysis seen by the Guardian suggests that growing numbers of victims of domestic violence are taking their own lives. Campaigners are now calling for the circumstances that led to these deaths to be investigated.

The Guardian recently reported on the case of Georgia Barter, whose suicide after a decade-long campaign at the hands of her former partner Thomas Bignell was judged by a coroner to be unlawful killing – only the second time in English legal history that such a conclusion has been reached. Despite this, no police investigation into Bignell’s role in Barter’s death has ever been launched and the Crown Prosecution Service says there is insufficient evidence to bring charges.

Inquests have a different burden of proof to criminal courts, finding on the balance of probabilities, rather than the criminal threshold of beyond reasonable doubt. There is no criminal due process and nobody is convicted or acquitted.

In Katie Madden’s case, although the coroner acknowledged that a toxic relationship contributed to her death, he did not make any finding of unlawful killing. Almost two years on, Madden’s family say Russell has not been investigated in relation to any of the inquest findings or any alleged abuse. This is despite admitting at the inquest that he gave Madden a black eye weeks before she died.

Police closed the assault investigation just days after Madden was found hanged at her home in Lowestoft, Suffolk. “The idea that it would just be dropped because she died – it should never be the case,” her mother says.

‘Her happy ever after’

“You just couldn’t have wished for a better mum and person,” Sutton says of her daughter. “She was very generous. She would give anybody her last penny. She would give anybody a lift.”

Growing up, Sutton remembers her daughter as a “bundle of fun and a very lively girl” who often had her head in a book. It was when Madden was about 12 that Sutton noticed a “massive change” in her daughter. “She wouldn’t get out of bed,” Sutton says. “She wouldn’t tell me anything.” Much later, Sutton discovered Madden had been sexually abused.

As her teenage years passed, Madden began drinking heavily and going missing. Sutton felt powerless to protect her daughter and she spent a brief period in care. At 16, she dropped out of school after becoming pregnant with her first child, she began self-harming and using cannabis. She also tried to take an overdose – her first attempt at suicide.

She was diagnosed with anxiety, depression, borderline personality disorder and emotionally unstable personality disorder. Sutton says Madden had spells of stability, was devoted to her children, and eventually got her own house in Lowestoft.

However, she also recalls that many people “took advantage” of her daughter, using her home to drink alcohol and take drugs. “Most of Katie’s friends, I wouldn’t even call friends, I would call them acquaintances,” Sutton says. “She never really understood how vulnerable she was. I said to her: ‘Can you not see that these people are taking advantage of you and your roof over their heads?’”

However, by late 2016, Sutton remembers Madden as being in a “good place”. It was then she met Russell. She told her mother she thought she had finally got her “happy ever after”.

Throughout the course of our three-hour interview, Sutton refuses to say Russell’s name, describing him only as the “alleged perpetrator”. She recalls being uneasy in his company from the outset. When she first met her daughter’s new partner over a meal, she says she “wasn’t 100%” but tried to convince herself she was being overprotective. “Mothers sit on the fence to begin with,” she says.

Madden soon fell pregnant with the couple’s first child, who was born in 2018. It was around this time she received a disclosure through Clare’s law, otherwise known as the domestic violence disclosure scheme, warning Madden of Russell’s past.

At Madden’s inquest, Russell agreed that he had “significant previous involvement” with the police, including one conviction for “physically assaulting a woman”.

A referral was made to a multi-agency safeguarding hub in light of the Clare’s law disclosure but the case was closed before any safety planning took place. In evidence, a senior social worker from Suffolk county council’s adult social services said this was because it looked like “a misdirected referral” as it did not indicate Madden “was subject to abuse or a crime”.

In a statement, the local authority said “lessons were learned by all agencies” after Madden’s death and added that it had “strengthened” its referral process “ensuring that safeguarding concerns about parents and children are shared promptly and appropriately” between departments. The council also said it had introduced “domestic abuse workers with dedicated training to better support adults in a child’s life who may be experiencing domestic violence”.

Madden had a second child with Russell in 2020. From this point, Sutton recalls, their relationship was “on and off”, something she remembers her daughter found hard to navigate. “Katie fell in love, this was her happy ever after,” Sutton says. “And suddenly it’s all [fallen] apart for a number of reasons.”

The next few years were punctuated by mental health crises. In November 2021, Madden spent four weeks in intensive care after crashing her car into a brick wall, scared her children would be removed from her. In June 2022, she asked for the children to be taken into care. “Katie’s children were her everything, but she felt that she was fighting so many battles,” Sutton says. A clinical psychologist suggested Madden would benefit from specialist cognitive behavioural therapy but she never received funding for it from any of the public services she was in touch with.

Sutton told the inquest that during this time, Madden was “fenced off” by Russell, and would sometimes spend days in bed without her phone as Russell “would smash it”. The inquest was also told that, in February 2023, Russell struck Madden on the face with her phone. Two months later, the court heard, Madden arrived at a contact meeting with her children with a cut to her eye and told Sutton she had been assaulted by Russell after a night out.

At the inquest, Russell accepted he had given Madden a black eye. He had been arrested on suspicion of assault occasioning actual bodily harm and forbidden from contacting her.

In the weeks that followed, Madden’s mental health problems spiralled. On 3 June, Sutton contacted her daughter to make arrangements for a picnic in the park with her children. Madden simply replied with a love heart.

The following evening, Sutton’s doorbell rang. It was a police officer. She knew instinctively what had happened. “I told her that she didn’t need to tell me,” Sutton says. “I told her what she’d come for.”

‘I said, go kill yourself’

Mason Jones was one of the last people to see Madden alive. In a statement, he told the inquest that he had only been friendly with her for about a month before she died. On the morning of 3 June, he recalled waking up to a string of messages from Madden, who seemed upset by some social media posts suggesting that Russell was with another woman in a hotel. At 7am, Madden and Jones went on a drive. Jones said he wanted to buy drugs to manage pain related to a medical condition.

Jones recalled that Russell “seemed to instigate” contact with Madden, despite his bail conditions. In his evidence, Russell claimed Madden called him. In response to Jones’s allegation that Russell said he was “in control of the town and would end [Madden’s] life if she didn’t do it herself”, Russell became agitated. “I didn’t say that,” he replied. “Get me the evidence … I wouldn’t say that. I’m a father. Why would I say that?”

He was asked by the coroner what the “general contents” of the call were. He said: “It was very erratic at the start. She was crying … she was just very panicky … I tried to reassure her but then it escalated into an argument. I ended up saying bad stuff.”

The coroner asked if Russell had told Madden she should hang herself. “I didn’t say hang herself,” he said. “There was a couple of references where I said, go kill yourself. Instantly, I went back on myself, and said, don’t be silly, don’t do that.”

Jones said he and Madden went to another friend’s house, where Madden “continued to argue” with Russell by phone before returning home. At about 12.45pm, she sent a message to Jones which read: “Thanks for putting up with me.”

Later that afternoon, Joe Hart, a friend of Russell’s, visited Madden’s home as she was looking after his dog. He told the inquest that Russell had told him Madden had “a noose around her neck”, but said: “At the time, I didn’t think it was a serious statement.”

Hart did not get a reply at Madden’s house. He threw an empty milkshake bottle at her bedroom window to try to get her attention but there was no response.

Neither man alerted the police, or Madden’s family. Hart said this was “because of what Katie was like … she’d quite regularly go off the map after she’d been wrecked”.

Russell disputed knowing Madden had a noose around her neck. He told the inquest: “She said that she was going to kill herself, she didn’t say she had a noose around her neck.”

When Russell was asked if he had failed to raise the alarm because he wanted Madden dead, he said: “You shouldn’t be speaking like that. I’ve got two children with her. Come on, man, that’s wrong. I didn’t want her dead. I dream about her every single day.”

Hart returned to the property at about 5pm on 4 June, the inquest heard. He said he contacted Russell, who encouraged him to break in if there was no response. When he entered the house, Hart found Madden hanged and called the emergency services.

‘There is no better detective than a mother’

On the way to Madden’s home, PC Bradley Congleton was told there was a history of domestic violence between Madden and Russell, which had culminated in a live assault investigation. He recovered Madden’s phone from the property. When he charged it, he told the inquest, he found messages from Russell encouraging Madden to kill herself. “There is no doubt in my mind, that is what he said to her,” Congleton said.

Congleton’s focus appears to have been on preparing a timeline of what had happened at the actual scene. In his evidence, Congleton said he considered it a priority to trace Russell to check his movements. At first, Russell would only speak to Congleton through an open window, the officer said. He recalled Russell saying that Madden had told him in her last hours that she “didn’t want to be alive any more” and was “intoxicated through drink and drugs”. Russell told Congleton he had been concerned but not been able to attend the address due to his bail conditions.

“I just cannot even begin to think how Katie was feeling,” Sutton says. “I know she was feeling hopeless … she was made to believe that everything was her fault.”

About a fortnight after Madden’s death, when Sutton was clearing out her daughter’s house, a letter arrived from the police, addressed to Madden. It said the assault case against Russell was being dropped.

“They must have known that Katie passed away,” Sutton says. “And they sent her that letter for me to open. And I was so upset, angry and cross about it, I ripped it up and I was so gutted that I did.”

Sutton says she contacted police as she had “a gut feeling there was more harm” in her daughter’s case. She was given Madden’s phone. “I read and listened to her messages,” she told the inquest. She described Russell’s messages as “awful”. “He told her to kill herself,” she told the court. “This is something he had said on many occasions.”

“There is no better detective than a mother,” Sutton says. “What Katie was saying would haunt me for the rest of my life. I just remember Katie saying in one of those voice notes, ‘You are giving me more reason to do it. You are not welcome at my funeral.’”

Sutton said she wanted police to review Madden and Russell’s communications in case they were able to build a case against Russell for coercive control; she claims officers told her they only had the capacity to examine a month’s worth of data. She recalls an officer who tried to “reassure us as a family” that the information about Russell would be held on file. “That’s no good to me,” she says.

The Guardian sent Suffolk police a series of questions about Madden’s case. The force said it was unable to answer them as her death was the subject of a domestic homicide review that had yet to conclude. Domestic homicide reviews examine the deaths of adults suspected to have suffered violence, abuse or neglect at the hands of a partner or family member. They are intended to identify lessons for the multiple agencies involved, rather than decide on whether any criminal investigation is merited.

The Guardian was not able to reach Russell for comment.

Madden was cremated in an intimate family ceremony. “She was never the centre of attention,” Sutton says. “She would never have wanted to be on parade.”

‘How many more women have got to die?’

After Madden’s inquest Parsley, the coroner, issued a prevention of future deaths report addressed to the police, social services, the NHS, the home office and the Department for Health. He said there was “no formal system in place” to support Madden, even though she was “known to be vulnerable” after the Clare’s law disclosure and that multi-agency safeguarding referrals made in respect of her children were “viewed in isolation, with no system in place to assess any additional risks posed to Kate herself”.

He said that the public bodies Madden was in contact with each suggested another should pay for her cognitive behavioural therapy, which she ultimately never received.

Sutton, who works in the NHS, says she hopes lessons will be learned after the tragedy and criticised “the lack of communication, the lack of empathy, the lack of professional curiosity, the lack of risk assessment, the lack of the standard stuff that should be happening” when it comes to dealing with alleged victims of domestic abuse.

Despite the police finding messages on Madden’s phone from Russell in which he told her to kill herself, the Guardian understands no police investigation into their relationship or the circumstances surrounding her death has been launched since her inquest.

“How many more women have got to die?” Sutton says. “Whether they take their own lives, or whether someone takes their life for them, how many more women, before something is done? How bad does it have to get before someone is prosecuted?”