Sonn Macmillan Walker

Sonn Macmillan Walker is a London-based criminal defence firm recognised as one of the largest and most highly regarded practices in its field. Founded as D.J. Sonn & Co in 1992, later becoming Sonn Macmillan and merging with Walkers in 2006, the firm has more than 20 fee-earners dedicated to defending clients in criminal proceedings. The practice undertakes all types of criminal and related civil cases, with particular expertise in homicide and serious crime, drugs offences, sexual offences, money laundering and complex fraud, confiscation proceedings, cash seizures, account freezing orders, motoring offences and extradition. The firm has a strong track record in serious and complex crime, including murder and attempted murder, substantial frauds, currency counterfeiting, drug-related matters and regulatory prosecutions, and is regularly involved in high-profile cases. A dedicated Crown Court team and in-house higher courts advocates provide continuity of representation from the police station through to Crown Court trial, while solicitors maintain a daily presence in magistrates’ courts across London with a strong success rate in contested matters. The firm undertakes significant privately funded work where legal aid is unavailable or not sought, combines sensitivity to client needs with robust advice when appropriate, and delivers expert support on complex, document-heavy allegations that may span months or years. Ongoing representation includes fraud and money laundering cases prosecuted by the Crown Prosecution Service, the Serious Fraud Office and the FCA. Leadership includes managing director Euan Macmillan, a solicitor with more than 30 years’ experience and a daily presence in the magistrates’ court; and David Sonn, noted for fraud and money laundering defence, including securing sole acquittals in the 2017 HBOS Reading case and in a seven-month Birmingham Crown Court trial concerning a film tax avoidance scheme, with additional expertise in motoring offences from minor speeding to causing death by dangerous or careless driving, excess alcohol, and matters involving planning enforcement notices, HMO regulations and health and safety prosecutions. The extradition practice is led by Katy Smart, whose team appears daily at Westminster Magistrates’ Court and has achieved notable successes in the Magistrates’ Court, High Court and Supreme Court.