A mother who stabbed a vulnerable man to death and then tried to blame her ex-boyfriend has been jailed for life. Kayleigh Smart knifed 34-year-old Liam Collier nearly a dozen times while in the midst of a schizophrenic episode.
The two had earlier exchanged "flirty" messages on Facebook and shared a lengthy video call before the victim paid for his killer to take a taxi to his flat on Sherlock Avenue in Haydock. They then drank vodka together before she launched into the attack, delivering a series of fatal blows with the weapon before he fell from a first floor window.
Smart thereafter disposed of the knife and told police her former partner, who she had previously accused of domestic abuse, was the perpetrator and alleged that Mr Collier had drugged her. But the 40-year-old, who has an "extensive history of treatment for mental ill health", subsequently changed her account and claimed she had armed herself for her own protection as she believed she was being "set up".
Life sentence with minimum of eight years
While Smart was initially charged with murder, she later admitted manslaughter on the grounds of diminished responsibility. The Crown Prosecution Service accepted this guilty plea after medical experts found she had a "grossly distorted" perception of reality at the time of the attack.
Returning to Liverpool Crown Court to be sentenced this morning, Tuesday, Smart was handed a life sentence with a minimum term of eight years. Several of Mr Collier's family members in the public gallery were heard to cry "yes" as she learned her fate.
Appearing via video link to Guild Lodge, a secure mental health hospital in Preston, Smart was also given a Section 45A hospital order. This means that she will remain in the psychiatric unit until deemed fit for discharge from treatment, at which stage she will be transferred to prison.
Judge's sentencing remarks
Sentencing, Judge Brian Cummings KC told her: "I am entirely satisfied the crown's decision is a proper one and taken after only very careful consideration of the evidence, including extensive psychiatric evidence. In my judgement, at the time you killed Liam Collier, the level of responsibility that you retained is best described as medium."
"In terms of aggravating factors, firstly, the victim was particularly vulnerable due to disability. Secondly, the offence involved the use of a weapon. Thirdly, the victim was caused significant mental and physical suffering before he died. I recognise that many, perhaps most, unlawful killings will involve a degree of physical and or mental suffering prior to death."
"However, I am satisfied that the suffering experienced by Liam Collier went substantially beyond that. He was essentially trapped, helpless and in terror of his life and suffered multiple knife injuries before either jumping or being propelled out of a first floor window."
"Fourthly, you committed the offence under the influence of alcohol or drugs. Fifthly, you have relevant previous convictions, albeit none of your convictions approach the seriousness of the present offence. I accept that you have had long standing mental health problems. I accept that you have shown a degree of remorse."
"Stripped of any mental health explanation, this was simply the horrifying and completely unprovoked killing with a knife of an inherently vulnerable young man. The offence could scarcely be more serious. Therefore, I must impose a sentence of life imprisonment."
"In my judgement, it is entirely appropriate that there should be a penal element to the disposal in your case. Your history has demonstrated that the risk factors that most need managing are more effectively managed by probation services under licence, rather than community mental health services."
"What this means is that you will be detained in hospital for as long as necessary for treatment purposes. It is possible that you may never be released from hospital. If you are released, you will be transferred to prison. It will be then for the Parole Board to consider whether and when you are suitable to be considered for release into the community."
Attack details and victim impact
Andrew Thomas KC, prosecuting, previously described how, at the time of the incident, Smart had recently separated from her ex-boyfriend and was living in supported accommodation for women, but had not been taking her medication for paranoid schizophrenia. She and Mr Collier, who himself had significant additional needs, then began messaging on May 2 last year before sharing a 50-minute video call.
Smart then arrived at his home in a taxi, arranged by him, shortly before 9pm with her belongings packed in a number of bags. He then gave his visitor a drink of vodka upon her arrival before going to the shop to buy another bottle.
But Smart then launched into her fatal assault at around 10.30pm, when muffled shouts were heard from the flat before Mr Collier opened his window and called for help. Mr Thomas told the court: "He was shouting for help and saying he was being stabbed. He eventually fell from the window. A thud can be heard as he strikes the ground."
While it was not possible to determine if Mr Collier had jumped or was pushed, he earlier desperately dialled 999 pleading for help while begging Smart to stop. He said in this call: "I'm getting stabbed. F*** off. Help me, please. I've done nothing wrong. Please, I am getting stabbed."
Mr Collier then fell silent and did not respond to questions from the call handler. Officers thereafter found him unconscious in the front garden with multiple stab wounds. Despite 45 minutes of medical intervention, paramedics and a critical care doctor were unable to restore cardiac function and Mr Collier was confirmed dead at 11.30pm. A post mortem investigation found he had sustained a total of 11 stab wounds, with a pathologist having recorded a cause of death of injuries to the chest.
Mr Collier's mum Sonya Whitfield read a statement to the court, in which she said: "That night changed my life forever. No mum should have to hear those words about their child. What hurt so much was how vulnerable Liam was. He deserved to be safe in his own home. I go past his flat and I see that window open and that tent in the garden. That will haunt me forever."
His sister Amy Collier added from the witness box: "I'm not the person that I was before Liam was taken from us. There is a constant sense of sadness I carry with me. I have to live with the consequences for the rest of my life. His life didn't end with his murder. It changed me and my family and has taken away a future we should have shared with him."
In a statement read to the court on his behalf, Liam's dad Stuart Collier meanwhile said: "We would give anything to hear his voice again, see his smile and see him walk through the door. His life cannot be replaced, and the space left in our family cannot be filled. We will carry Liam in our hearts for the rest of our lives but will always wish he was here with us."
Investigation and mental health history
Merseyside Police never found the weapon used in the attack, with Smart said to have either cleaned the knife to "disguise it" or thrown the weapon from the flat into the overgrown garden. Upon arrest, she first blamed her former partner for the assault and claimed he had followed her to the address before carrying out the stabbing.
Under interview, Smart went on to allege that Mr Collier had "drugged" her with the vodka. She was charged with murder on May 4 2025 and was remanded in custody at HMP Styal.
But Smart, of no fixed address but from Billinge, continued to refuse to take her medication and, the following month, reported delusional symptoms "such as that an officer was the devil and the healthcare team were trying to poison her". She was admitted to Guild Lodge on July 9 as a result was unfit to enter a plea to the murder count.
Smart later said she believed people at her supported living accommodation were trying to poison her and her "life is broadcast on a TV channel and there are cameras watching". She was also said to have changed her account by saying she had armed herself with a knife because she "convinced herself that [Mr Collier] was going to attack her and so started stabbing him".
Smart was later deemed fit to plead at the beginning of 2026 and was scheduled to stand trial in June. However, she pleaded guilty to the lesser charge of manslaughter on the grounds of diminished responsibility.
The court heard Smart's history of mental health dated back to 2002 and coincided with the start of her criminal record, which included offences of battery, theft, fraud, threatening behaviour and criminal damage. She also has a conviction from December 2019 for making threats with a bladed article.
An incident in 2015, when Smart reportedly held a knife to her boyfriend's throat, was also reported to mental health services. She was first detained under the Mental Health Act in 2014 due to borderline personality disorder, followed by at least two other periods of compulsory detention between 2016 and 2018 due to "drug psychoses".
Mr Thomas said Smart had a history of misusing alcohol and drugs, including opioids, cocaine, stimulants and cannabis, and had been suffering from psychotic episodes since around 2015. She was officially diagnosed with paranoid schizophrenia in July 2023 and began treatment with anti-psychotic medication.
Smart then spent a period of time at Guild Lodge, where she remained as a voluntary patient until August 2024. Once released, she continued her treatment in the community, but, in early 2025, stopped attending appointments and taking her medication and later admitted she was drinking a litre of vodka each day.
For several months, Smart was said to have lived a "chaotic lifestyle with unstable accommodation". She eventually moved into a caravan with a boyfriend and disengaged with the community mental health team before securing a tenancy in a supported living flat.
Michael Hayton KC, defending, said on Smart's behalf on Friday last week "The court faces a difficult exercise. The level of violence was extreme, an extended family has lost someone they dearly cared for and that person is blameless."
"He was doing a kind act, and he was repaid in the most brutal of ways. The defendant offers her profound apologies and regret. She is someone whose mental health is at the heart of it."
"This lady's major problem is her mental health. Her other issues have led to little more than minor criminality. It is the psychosis that has led to the homicide. That is where the focus of the court should be."
