In a significant judgment on expert evidence and alleged alienating behaviour, the president of the Family Division reaffirmed that expert evidence cannot substitute judicial fact-finding.
The Rt Hon Sir Andrew McFarlane handed down judgment in Y (Experts and Alienating Behaviour: The Modern Approach) in February at the Royal Courts of Justice in London, following a January hearing concerning a Part 18 application to set aside findings of parental alienation and emotional abuse relating to the mother of two children, during previous hearings which took place in 2019 and 2020.
In December 2014, the parents of the children separated and subsequently divorced. “Extremely serious” allegations of abusive behaviour were made by each parent against the other. In 2019 a CAFCASS officer suggested a court should determine “where the truth lies” and a fact-finding hearing was ordered.
At the hearing in October 2019, the court heard evidence from unregulated psychologist Melanie Gill, who had been instructed following an application by the children’s guardian.
In her report, Ms Gill described herself as a “psychologist, forensic assessor and forensic consultant… with her own practice,” despite not having a clinical or therapeutic practice in which she saw patients.
Ms Gill’s report claimed the mother had traits of narcissistic and histrionic thought processing caused by unresolved trauma caused by her own mother, and had used her children to support projected vengeful anger against their father. The report further found extensive evidence the children were being actively alienated from their father by their mother. The mother had applied for permission to instruct an alternative psychologist, which was refused.
A report from the children’s guardian endorsed Gill’s recommendations that the children would be at significant psychological risk if they continued to live with their mother and claimed the “strongly expressed” views of the children could not be “given much weight” due to the “negative influence of their mother and the children’s alignment with their mother”.
In a December 2019 hearing, the mother’s counsel submitted that allegations of serious domestic abuse against the father should be determined by a fact-finding hearing. “The allegations made by the mother, if found to be proved, must have an impact upon the shape of the case,” Ms Fenella Cooil submitted.
“It cannot be right, the mother says, that domestic violence and abuse – which she says she has suffered at the hands of the father – does not contextualise the mother’s allegations and the effect upon her and the children. Those allegations are, in substance, of attacks and sustained physical and emotional abuse in respect of which there is corroborative police and medical evidence.”
Counsel for the father and children’s guardian urged the judge to hear no further evidence.
Without hearing from any other witness and without the court having determined the mother’s application for permission to appeal, the judge found that the children had been alienated from their father as a result of their mother’s “highly negative attitude towards him” and made an order directing the children – a girl (X) at that time aged 12 and a boy (Y), 9 – should move immediately to live with their father.
An appeal against the order was refused. From the end of 2019 until 2025 the children had no contact with their mother, apart from one incident when they met by chance in a local shop.
The mother continued to seek contact and in 2021 issued an application to vary the child arrangements order. At a case management hearing, the court directed it would “not be dealing with any challenge to the report of Melanie Gill”.
The application was dismissed at a final hearing in April 2022, the no contact order was maintained, and the court imposed a prohibition on the mother from bringing any further applications regarding the children without the court’s permission for the next year. Permission to appeal that order was refused.
Early in 2025, the daughter (X), by then aged 18, had moved briefly to live with her mother. Later in 2025, the boy (Y), by then aged 15, left his father’s care voluntarily to live with his mother. However, in light of the previous court’s findings, he was removed from his mother’s house and taken into police protection during the night. After spending time in foster care, the court agreed he could stay with a friend of his mother.
In April 2025, the mother issued her Part 18 application to reopen and set aside the findings made in 2019 and 2020 based on Gill’s opinion.
The application asserted “very significant new evidence and information existed to cast doubt on earlier findings,” including the approach to parental alienation taken in Re C (Parental Alienation; Instruction of Expert) and the extensive guidance on alienating behaviour issued by the Family Justice Council in December 2024.
The guidance, Sir Andrew said in his February judgment, was “clear that unregulated experts, such as Ms Gill, should not be instructed in cases of alleged alienating behaviour. The advice is that expert evidence should only be directed after any findings of fact have been made and should not be relied upon for the purpose of making such findings”.
In Re C, Sir Andrew had heard an appeal against a judge’s refusal to reopen a fact-finding decision in a case in which Ms Gill had been the expert witness.
Summarising his approach to Re C in the February judgment, Sir Andrew said:
“With regard to ‘parental alienation’, I made the following short, but hopefully very clear, observation:
“Before leaving this part of the appeal, one particular paragraph in the ACP skeleton argument deserves to be widely understood and, I would strongly urge, accepted:
“Much like an allegation of domestic abuse; the decision about whether or not a parent has alienated a child is a question of fact for the Court to resolve and not a diagnosis that can or should be offered by a psychologist. For these purposes, the Association of Clinical Psychologists-UK wishes to emphasise that ‘parental alienation’ is not a syndrome capable of being diagnosed, but a process of manipulation of children perpetrated by one parent against the other through, what are termed as, “alienating behaviours”. It is, fundamentally, a question of fact.’
“It is not the purpose of this judgment to go further into the topic of alienation. Most Family judges have, for some time, regarded the label of ‘parental alienation’, and the suggestion that there may be a diagnosable syndrome of that name, as being unhelpful. What is important, as with domestic abuse, is the particular behaviour that is found to have taken place within the individual family before the court, and the impact that that behaviour may have had on the relationship of a child with either or both of his/her parents. In this regard, the identification of ‘alienating behaviour’ should be the court’s focus, rather than any quest to determine whether the label ‘parental alienation’ can be applied.’”
Reaffirming that determining disputed allegations is a judicial function and cannot be outsourced to an expert witness, Sir Andrew continued:
“It is inappropriate for experts to be asked to step into fact-finding or determination of alienating behaviours – as such, the timing and type of expert evidence needed is crucial.”
Setting the earlier findings of alienation and emotional abuse aside, he concluded:
“…any future consideration given by a court as to the welfare of Y, are to be evaluated without any reference to the report and evidence of Ms Gill or to those findings.”
Y was present throughout the hearing, represented by his own legal team. Following the decision to set aside the court’s previous findings and make a new order for him to live with his mother, he told The Bureau of Investigative Journalism he “finally felt heard”.
He added: “I’m so grateful to be home with my mum finally and to feel happy again.”
Y (Experts and Alienating Behaviour: The Modern Approach) [2026] EWFC 38
