Sebastian prosecutes and defends in the Crown Court, as well as appearing in various crime-related public law proceedings, including prison law and civil proceeds of crime work.

Sebastian has particular experience in serious and complex crime having been instructed as junior alone in cases of serious violence (including s.18 and kidnap), firearms offences and international class A drugs conspiracies. Sebastian also acts regularly as a led junior in paper heavy, multi-defendant matters.

Sebastian also has an interest in financial crime proceedings and has been instructed as junior alone and led junior in a number of fraud, money laundering and computer misuse cases (including cases involving the layering of proceeds of crime via cryptocurrency transactions and frauds committed by members of the Metropolitan Police Service). He has experience advising on private prosecutions in these areas and has acted in numerous civil and criminal Proceeds of Crime proceedings (including cases with benefits exceeding £1 million). He is adept at getting to grips with large page counts of technical transactions rapidly.

Sebastian has been instructed by local authorities, police areas, the Insolvency Service, HMRC and on behalf of defendants in respect of this work and related regulatory work (including housing matters, civil restraint orders and fraudulent builders). He has also recently acted as second junior to Duncan Atkinson KC in his role giving expert evidence to the Post Office Horizon Inquiry as to decision making in the criminal investigation and prosecution of such cases.”

CPS Panel appointments

General Crime Level 3
Serious Crime Level 3
Counter Terrorism Level 3
Fraud Level 3
Proceeds of Crime Level 2

Key cases & testimonials

Op F [2024] – Instructed as junior alone for the defence in a 15,000+ page conspiracy to supply and produce cannabis. The case involved messaging evidence, significant surveillance, cell site and various search and seizures. There was novel legal argument as to the admissibility of evidence following the use of AI tools to initially translate messages on devices (and the resulting successful exclusion of late served messaging).

Op T [2024] – Instructed as junior alone by CPS POCD for confiscation proceedings against six defendants in relation to various conspiracies to burgle and convert criminal property. The case related to the theft of a £3.5 million tiara and of various high-end watches and items of jewellery, including from a premier league footballer’s home. Advised on disclosure (including cross-disclosure); the ability to agree orders where other defendants are challenging benefit figures; and the adjournment of compensation. Litigated issues included the valuation of benefit in relation to stolen items (insurance, open market, second hand replacement or constituent parts); and the valuation of hidden assets in circumstances where jewellery and watches were never recovered from the fence. There was contested expert valuation evidence. In respect of the Hatton Garden fence a benefit in excess of £5.5 million found and findings of available assets of over £600k and hidden assets of £1.5 million. Compensation of over £2.2 million was apportioned to victims and insurers.

Op N [2024] – Instructed as led junior in the prosecution of nine defendants (all university students) for involvement in large-spread violent disorder in Leicester City Centre which culminated in serious stab wounds to one (wounding with intent) and the attempted stabbing/bottling to the head of another (attempted wounding with intent). The case involved extensive review of numerous CCTV cameras to identify defendants and their actions, tracking some defendants from their halls of residence to the incident (which was largely caught on poor quality footage).

Coverage available here.

Op M [2024] – instructed as led junior by the East Midlands Complex Casework Unit in the prosecution of 14 defendants in respect of cross-border conspiracies to steal and burgle ATMs wherein over £600,000 was stolen in 17 separate attacks, as well as multiple vehicles and significant damage caused. The case involved separate Scottish and English police investigations, extensive call data evidence and CCTV and contested issues relating to jurisdiction and the admissibility of Scottish no-comment interviews.

Coverage available here.

R v R [2024] – instructed as junior alone by the East Midlands Complex Casework Unit in the prosecution of offences of production and possession of a chemical weapon, relating to the production of Ricin. The case involved legal argument as to the definition of production, contested expert evidence on Ricin and the engagement of the Attorney General’s Office whose consent was required for prosecution.

Op S [2024] – instructed as junior alone for the lead defendant in an NCA investigation into the bulk import and export of Mephedrone prosecuted by the CPS Serious Economic, Organised Crime and International Directorate. Prosecution case opened on the basis he was the lead individual in England and Wales and responsible for directing others. Following a multi-day Newton hearing the defendant received a suspended sentence order.

Op R [2023] – instructed as led junior by the East Midlands Complex Casework Unit in relation to the prosecution and conviction of five defendants in relation to the importation (and seizure) of over 50kg of class A drugs and related money laundering. The evidence comprised detailed call data analysis, evidence from witnesses abroad (Belgium and the Netherlands), analysis of financial transactions, and bad character evidence from jurisdictions abroad. Worked closely with the FI to produce new analysis and presentation material with pleas from the defendants facing money laundering charges following on the day the FI was to give evidence.

Coverage available here.

Op S [2023] – instructed as led junior by the Thames & Chiltern Complex Casework Unit in relation to the prosecution and conviction of four defendants for a conspiracy to kidnap and blackmail, in relation to an OCG’s kidnap of a debtor over a five day period and the blackmail of his family. The case involved the admission of the complainant (and family member’s) evidence as hearsay due to fear following a voire dire, as well as the presentation of supporting evidence from firearms officers, cell-site, and financial information. My role included calling evidence from anonymous firearms officers, presentation of the applications for admissibility, handling of the vulnerable complainants and extensive disclosure reviews following significant non-D bad character applications.

Coverage available here.

Op L [2023] – instructed as led junior by the CPS Serious Economic, Organised Crime and International Directorate in relation to the prosecution of five defendants in relation to conspiracies to possess firearms with intent to endanger life and supply class A drugs in wholesale quantities. This was a case principally based on Encrochat evidence and involved challenges to both the admissibility and reliability of that evidence, as well as attribution of handles. Due to illness of leading counsel, called contested expert evidence on the reliability and obtaining of Encrochat data as well as contested expert DNA evidence.
Coverage available here.

Op Z [2022-2023] – instructed as led junior by the East Midlands Complex Casework Unit in relation to the prosecution and conviction of twelve defendants over two trials in inter-linked conspiracies to supply Class A and B drugs over a three year period. The evidence in the case included cell site analysis, mobile phone downloads and search and seizures.

Op H [2022 – 2023] – instructed as disclosure junior in the prosecution of 11 defendants for murder. The murder was a planned enterprise set against the background of significant organised drug supply and which resulted in a revenge attack. It generated thousands of items of unused material and over 768 hours of CCTV footage.
Coverage available here.

R v NN [2021] – acted for defendant from whose home a large amount of cocaine was seized. Her fingerprints were found on the containers in which it was kept. In interview she made admissions to assisting in the supply of drugs. Instructed an expert in relation to her mental health issues and Crown offered no evidence following service of a skeleton to exclude the interview on the grounds of those issues and the lack of an appropriate adult.

R v M [2021] – acted for defence in contested confiscation proceedings where Crown sought benefit of £1.1 million and hidden assets. Benefit determined at £550,000 following submissions on the approach to valuation and accepted no hidden assets.

Sebastian is professional, intelligent, focused, unfalteringly diligent, flexible, robust, and eloquent, with an irresistible advocacy style. He is without doubt one of the most impressive barristers around.Legal 500, 2025
Sebastian is an absolute star. He is go-to person for complicated points of law, calm and collected under pressure. He is always one step ahead of the opposition.Legal 500, 2025
Sebastian thoroughly understands and analyses substantial and complex evidence and quickly and efficiently incorporates the changing evidential picture into his analysis.Legal 500 2024
Sebastian has an extraordinary ability to analyse, retain and deal with complex details in a case. In court, he is both forensic and sympathetic to his tribunal. His ability is far beyond his year of call.Legal 500 2024

Further information

BA (Hons) Law, 2:1 (University of Nottingham)

LLM in Criminal Justice, Distinction (University of Nottingham)

Bar Professional Training Course, Outstanding (The City Law School)

Awards and Scholarships

Best Graduating Masters Student in the School of Law 2014-15, University of Nottingham (2015)

Prince of Wales Scholar, Gray’s Inn (2017-2019)

British Academy of Forensic Sciences Prize for best performance in Advanced Criminal Litigation on the BPTC, The City Law School (2019)

Ann Goddard Scholar, Gray’s Inn (2021)