Firm Profile > Sonn Macmillan Walker > London, England

Sonn Macmillan Walker

Crime: general Tier 2

'Highly professional firm' Sonn Macmillan Walker has recently advised on complex cases of terrorism, sexual offences, murder, extradition, drugs matters and motoring offences. Tim Walker, Amy Cox and David Sonn share leadership of the practice.

Practice head(s):

Tim Walker; Amy Cox; David Sonn


‘A highly professional firm which provides an excellent service to their clients. They go to exceptional lengths to explore potential legitimate defences available to a client and areas of inquiry which ensure their clients have a fair trial. They combine advocacy with litigation skills to ensure they provide a complete service.’

‘Tim Walker and David Kitson both have extensive expertise in complex criminal cases, including murder and terrorism. They go out of their way to ensure that their clients are engaged with every aspect of the proceedings.’

Sonn Macmillan Walker is one of the largest and most highly regarded criminal defence firms in London. All types of criminal (and related civil) cases are undertaken and the firm has particular expertise in the following areas: money laundering and serious fraud (including restraint, confiscation and cash forfeiture), serious crime, protest/public order/civil rights, motoring offences, regulatory and extradition.

The firm: Founded as D.J.Sonn & Co in 1992, shortly thereafter becoming Sonn Macmillan and in 2006 merging with Walkers, the firm has more than 20 fee-earners dedicated to the defence of those facing criminal proceedings. The firm has a strong reputation for its conduct of serious and complex crime and is regularly involved in high-profile cases. It has considerable experience of acting for clients in murder and attempted murder cases, substantial frauds and many other serious cases, ranging from sexual offences, to currency counterfeiting, drug-related matters and regulatory prosecutions. In 2011, Sonn Macmillan Walker was one of five firms who represented bereaved families in connection with the 7/7 inquests, one of the most significant legal events of recent years. The firm also represents clients facing extradition, both in the Magistrates’ Court and on appeal.

The firm has a dedicated team of solicitors for the more serious Crown Court cases and its in-house higher courts advocates ensure continuity of representation for clients from the police station to the conclusion of their Crown Court trial. Its solicitors are also ever-present in the magistrates’ courts around London and enjoy an outstanding success rate in contested matters.

The firm undertakes a significant amount of privately funded work where legal aid is either not available or not applied for. All of its staff members are very sensitive to the needs of clients and recognise that being the subject of criminal proceedings is a stressful experience. Equally, they do not shy away from providing robust advice when appropriate.

Types of work undertaken: The practice undertakes defence work in all types of cases, with an emphasis on serious crime, fraud and money laundering. Expert advice is offered in complex allegations that can take months or years to come to trial and involve many thousands of pages of documentation. The firm is continuously acting in fraud and money laundering matters being prosecuted by the Crown Prosecution Service, the Serious Fraud Office and the FCA.

Tim Walker is well known for his skills in political and animal rights cases. He was instructed in the longest ever animal rights extremism trial and in a highly publicised case involving the key organisers of the Stop Huntingdon Animal Cruelty campaign. Tim also heads the firm’s Crown Court department and represents clients charged with the most serious offences. Recent acquittals include a client charged with importing over 400kg of cocaine, several clients accused of murder and a multimillion-pound advance fee fraud. He has also acted for clients accused of terrorism offences. He is also known for his work in defending sexual offences.

David Sonn is highly experienced in large-scale fraud and money laundering cases. His client was the only defendant acquitted in 2017 in the HBOS fraud committed at the Reading office. There were more than 200,000 pages of served evidence. His client was also the only client acquitted in a seven month trial at Birmingham Crown Court concerning a fraudulent film tax avoidance scheme. David Sonn is also a founding and committee member of the Association of Motor Offence Lawyers. Road traffic expertise ranges from minor speeding offences to more serious charges of causing death by dangerous and careless driving, dangerous driving, and driving with excess alcohol.

Katy Smart heads an extradition team that has a daily presence at Westminster Magistrates’ Court, where all extradition cases commence. The firm has had notable recent successes in all courts, from the Magistrates’ Court to the High Court and Supreme Court.

Department Name Email Telephone
Senior partner David Sonn
Managing partner Euan Macmillan
Number of UK partners : 3
Number of other UK fee-earners : 25