Claire Mawer
- Criminal Appeals Lawyers Association
- Criminal Bar Association
- South-Eastern Circuit
- Lord Mansfield Scholar (highest BPTC scholarship), Lincolns’ Inn
- BPTC, The Inns of Court School of Law
- Graduate Diploma in Law, The College of Law
- MA History, University of Cambridge
Instructing Claire Mawer
To instruct Claire or for any further information please contact our clerks on +44 (0)20 7440 8888 or clerks@2br.co.uk.
Claire Mawer is a highly experienced advocate, regularly instructed as a sole or led junior to defend in serious criminal matters in the Crown Court, High Court, Court of Appeal and the Youth Court.
Claire is routinely instructed to defend in cases covering the full spectrum of criminal offences, including: large conspiracies; drugs; firearms; burglary & robbery; serious violence (including murder, attempted murder and s.18 GBH); fraud; sexual offences & driving offences.
Claire is particularly experienced in appellate crime and the representation of young defendants (children and young adults) and vulnerable defendants, including women who have entered the criminal justice system due to the experience of trauma and abuse, and defendants who suffer with mental disorders.
Primarily because of her experience in representing vulnerable defendants, Claire is often instructed to run legally complex defences, including: modern slavery and child criminal exploitation; fitness to plead & insanity; and the partial defences to murder.
Current defence instructions include: two separate murder cases (both as a led junior at the Central Criminal Court and Inner London Crown Court); junior alone in a 750kg cocaine importation conspiracy; rape; and familial sexual offences.
Practice Areas
Claire is an experienced appellate advocate in the Court of Appeal and High Court, as both a junior alone and led junior. Claire has appeared in several high-profile conviction and sentence appeals, many of which have been reported.
Claire has been singled out for instruction by the Registrar for instruction in a ‘mercy-plea’ appeal against sentence, as a result of her previous success in representing the Appellant in an appeal against sentence in circumstances where the Appellant was diagnosed with terminal cancer and likely to die in prison, but for the successful appeal.
Examples of Claire’s recent, notable work and reported cases include:
- R v O [2024] EWCA [2024] EWCA Crim 171 – Represented the Appellant in a successful appeal against a sentence in circumstances where the Court of Appeal upheld grounds of appeal predicated on a failure by the sentencing judge to give any or sufficient regard to the Appellant’s history of child exploitation and immaturity.
- R v FM [2020] EWCA Crim 1798 – Led junior for the Appellant in a high-profile, successful appeal against murder conviction involving a young woman originally convicted of murdering a violent partner. The case involved the admission of fresh evidence relating to the experience of coercive and controlling behaviour and sexual violence as relevant to the partial defences of diminished responsibility and loss of control.
- R v D [2021] 1 Cr. App. R. 18 – Represented the Appellant (described by the press as Britain’s most dangerous woman) in a successful appeal against sentence and co-joined conviction appeal.
- R v SOL [2020] 1 Cr. App. R. (S.) 32– Represented the Appellant in this appeal against the imposition of a sentence of immediate imprisonment, in which the Court of Appeal issued guidance as regards the imposition of suspended sentences and treatment of age/lack of maturity in the assessment of culpability and appropriate sentence.
- O v DPP [2018] 1 Cr. App. R. 27, [2018] Q.B. 1086, [2018] 2 W.L.R. 1725 – Instructed as sole junior in this leading authority relating to the availability of self-defence to offences of assaulting and/or obstruct police officers.
Claire is a former long-standing member of Justice for Women (“JfW”), a group of women lawyers who bring appeals and campaign on behalf of women who have been convicted of the murder of a violent partner. Claire was a spokesperson for JfW during the campaign relating to the appeal of Sally Challen, chairing events, appearing as a panel member at press conferences, and giving live interviews to BBC News (television and radio) ITV & Sky News. Claire also organised and was a panel member (alongside Harriet Wistrich and Helena Kennedy QC) at the 2018 celebration of JfW’s 25th anniversary.
Claire is also a committee member of the Criminal Appeals Lawyers Association.
Claire is hugely experienced in relation to defending youths and young adults charged with the most serious offences in the Youth Court and Crown Court.
Examples of recent instructions include:
- R v WO, Croydon Youth Court (certificate for counsel), December 2024, representation of child defendant prosecuted for multiple allegations of sexual offending. Partial Acquittals.
- R v EB, Guildford Crown Court, April 2023, representation of Defendant who turned 18 before being charged with and prosecuted for image offences. Successful application to stay proceedings due to delay and a failure by the CPS to properly apply youth charging guidance.
Claire previously worked as a consultant for the Youth Justice Legal Centre, where her work involved the publication of their legal guides and appeals against sentence with a particular focus on sentencing issues relating to young adults (those aged between 18 – 25).
Claire has authored or collaborated in the following publications:
- ‘Turning 18’ Practitioners’ Guide, June 2020 (author)
- ‘Child Criminal Exploitation’ Practitioners’ Guide, December 2020 (author)
- Criminal Behaviour Orders, Jan 2021 (collaborator)
- Trauma Involved Lawyering, May 2021 (collaborator)
- Sentencing of Young Adults L.R. 2021, 3, 203-217 Sentencing (co-author with Dr Laura Janes, legal director of the Howard League for Penal Reform and David Emanuel QC)
Claire has also presented at a number of Youth Justice seminars, including:
- ‘Turning 18’ Youth Justice Legal Centre training, June 2020 (alongside Mr Justice William Davies, youth justice lead at the Court of Appeal)
- ‘Turning 18’, London Criminal Court’s Solicitors Association training, June 2020
Claire Mawer is a highly experienced defence advocate, regularly instructed as a sole or led junior to defend in serious criminal matters in the Crown Court, Court of Appeal and High Court.
In general crime Claire is routinely instructed in the full spectrum of criminal offences, including: homicide (murder & manslaughter); drugs; firearms; conspiracy; burglary & robbery; serious violence including s.18 GBH; fraud; sexual offences & driving offences.
Claire is particularly experienced in the representation of young defendants (children and young adults) and vulnerable defendants, including women who have entered the criminal justice system due to the experience of trauma and abuse and defendants who suffer with mental disorders.
Primarily as a result of her experience in representing vulnerable defendants, Claire is experienced in running legally complex defences, including: modern slavery and child criminal exploitation; fitness to plead & insanity; and the partial defences to murder.
Examples of Claire’s recent defence cases include:
- R v GR, Central Criminal Court, April 2025, junior alone, representation of Defendant charged with causing death by careless driving. Acquittal.
- R v EDT, Ipswich Crown Court, March 2025, representation of Defendant charged with multiple counts of assault by penetration. Acquittal.
- R v WO, Croydon Youth Court, December 2024, representation of child Defendant charged with multiple sexual offences. Partial acquittals.
- R v AC, Wood Green Crown Court, November 2024, successful representation of Defendant charged with rape. Acquittal.
- R v N&N, Southwark Crown Court, September 2024, representation of a prison officer charged with computer misuse. Acquittal.
- R v AJG, Central Criminal Court, March – June 2024, junior alone, represented a female Defendant charged with perverting the course of justice who was prosecuted alongside four defendants charged with murder. Acquittal.
- R v PP, Cambridge Crown Court, February 2024, junior alone, represented a Defendant charged with multiple counts of rape. Acquittal.
- R v JA, Southwark Crown Court, December 2023, led junior (for D1) in a crypto currency fraud. Secured favourable sentence following a guilty plea.
- R v MH, Wood Green Crown Court, August 2023, represented a Defendant charged with assault PC in an incident arising from the BLM protests across the country. Successful submission of no case to answer.
Claire represents Respondents, at first instance and on appeal to the High Court, in extradition proceedings involving a wide spectrum of issues, including cases advancing Article 8 and Article 3 grounds.
Examples of Claire’s recent extradition cases include:
- R v PN, 2021. Represented the Requested Person at first instance and on appeal (permission granted) in an Article 8 appeal.
- R v PM, 2021. Successful representation of a Requested Person whose extradition was refused on the basis of Article 8 grounds, in circumstances where the RP’s son suffered with severe disabilities.
Claire is routinely instructed in a wide range of driving matters (on a privately funded and legal aid basis) from cases pleading special reasons and exceptional hardship through to serious driving offences including causing serious injury by dangerous driving and causing death by dangerous driving.
Claire receives instructions in cases involving serious fraud and related offending.
Examples of current instructions include a multi-handed money laundering conspiracy before Maidstone Crown Court.
Recent instructions include the representation of the first defendant in a Cryptocurrency money laundering conspiracy before Southwark Crown Court, which involved responding to applications for a Serious Crime Prevention Order and Directors Disqualification Order. R v A, Southwark Crown Court, December 2024.
Claire also has experience of disclosure review in a number of serious fraud cases, which include:
- Axiom Legal Financing Fund, 2021 (instructed as disclosure counsel by the SFO)
- Euribor, 2018 (instructed as disclosure counsel by Howard Kennedy LLP)
- Tesco, 2018 (instructed as disclosure counsel by the SFO)
Claire is regularly instructed as a sole and led junior in the full spectrum of homicide offences, including murder and attempted murder.
Claire is currently instructed as a led junior in murder cases before the Central Criminal Court and Inner London Crown Court.
Examples of recent instructions include:
- R v GR, Central Criminal Court, April 2025, junior alone, represented a Defendant charged with causing death by careless driving. Acquittal.
- R v JM, Wood Green Crown Court, August 2023, junior alone, represented a Defendant charged with attempted murder and s.18 GBH.
- R v A & Others, Central Criminal Court, October – December 2022, led junior, represented the first defendant in a multi-handed murder. Hung jury.
Claire is routinely instructed in cases involving allegations of serious sexual offending. Current instructions include cases of rape, sexual assault, assault by penetration and familial sexual offences.
Examples of recent instructions include:
- R v EDT, Ipswich Crown Court, March 2025, represented a Defendant charged with multiple counts of assault by penetration. Acquittal. The case involved making a detailed and successful application under s.41 YJCEA to admit over 300 pages of material relating to the Complainant and Defendant’s sexual history.
- R v DA, Wood Green Crown Court, November 2024, represented a Defendant charged with rape. Acquittal.
- R v PP, Cambridge Crown Court, February 2024, representation of Defendant charged with multiple counts of rape. Acquittal.
