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 is the author of a number of practitioner texts, including co-authoring the sentencing chapter in Archbold and Sentencing Principles, Procedure and Practice, and his academic work has previously been cited and endorsed by the Court of Appeal.

Prior to coming to the bar he worked for four years at the Law Commission and the Attorney General’s Office. At the Law Commission, Sebastian was the lead lawyer on what is now the Sentencing Act 2020, instructing Parliamentary Counsel on the drafting of the Bill and giving evidence to the Joint Committee during the Act’s passage through Parliament.

During this time Sebastian also taught criminal law at the London School of Economics. He continues to teach law at the University of Cambridge.

Key cases

Op S [ongoing] – instructed as led junior by the Thames & Chiltern Complex Casework Unit for a five defendant 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 involves cell site material, ANPR evidence and phone downloads as well as highly vulnerable witnesses.

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.

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.

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)