Mark Heywood KC has been ranked as a 'Star Individual' in the Chambers UK Guide to the Bar since 2013 and is a recognised leader at the Bar. He was awarded the Chambers UK Bar Crime Silk of the Year award 2018.
Mark Heywood KC is a former First Senior Treasury Counsel at the Central Criminal Court having held that post between 2015 & 2018. His practice is concentrated on the most serious of criminal work that comes before our Courts, at the Central Criminal Court, Administrative Court, Court of Appeal and Supreme Court. He has appeared in the High Court in civil contempt proceedings, most recently for a claimant Hong Kong Bank where the defendant was sentenced to 18 months and ordered to pay indemnity costs.
Since his role of Senior Treasury Counsel, Mark Heywood KC has primarily been involved in cases of alleged financial misconduct. He leads the prosecution team for the SFO in Op Glacier, the prosecution of a former Airbus subsidiary that was ordered to pay more than 30 million pounds ($42 million) after pleading guilty to corruption over contracts to provide military communications services for the Saudi Arabian National Guard, the trial against the directors is due in January 2023. He has provided pre-charge representations to a client that the SFO suspected had conspired to make corrupt payments contrary to s.1 of the Prevention of Corruption Act 1906 and s.1 of the Criminal Law Act 1977, and was interviewed about his actions in particular, the SFO suspects was involved in actions leading to agreements to make corrupt payments to Nigerian and Malaysian Government Officials, which was discontinued. Further successful pre-charge work includes advice given to an SFO suspect in relation to bribery and corruption involving Petrobas, the value of the contract was said could easily be up to $2 billion. Trial work has including Op Cullinan, a multi-company boiler room fraud involving the sale of diamonds that was dismissed at half time and Op Balaban, a £7m carbon credit fraud that was again dismissed at the close of the crown case.
Mr Heywood has considerable experience in cases of terrorism, large scale corruption, serious & organised crime and offences of homicide. He regularly provides advice to the Attorney General and Director of Public Prosecutions on a range of matters, particularly those being considered by the appellate courts as well as other governmental departments. Other work includes advising upon matters concerning gross negligence manslaughter involving the medical profession and litigation involving the SFO and FSA. He also advises in matters where a private prosecution is sought.
Cases have included the serial killer Levi Bellfield, Operation Crevice the longest running Old Bailey trial better known as the Fertiliser Bomb plot, Nicola Edginton the mental health patient convicted for the killing of an innocent bystander and the attempted murder of two others in Bexleyheath after a cry for help, the Supreme Court hearing of Gnango [2011 UKSC 59] on transferred malice/joint enterprise, Arthur Simpson-Kent who was sentenced to life for the murder of Eastenders actress Sian Blake and their two children. Recent defence work has included a murder trial in the Cayman Islands (R v.Sanchez).
Mark Heywood KC led William Davis in the prosecution of a company that manufactures total parenteral nutrition, which is supplied to vulnerable patients receiving nutrition intravenously. In 2014 a contaminated batch was supplied to hospitals treating severely premature babies. 19 babies developed infections as a result, and one died. After protracted and contentious litigation, the defendant company pleaded guilty to a health and safety offence and to offences under the Medicines Act 1968. The company was sentenced in April 2022.
Mark Heywood KC led for the Crown in this case involving a Swedish Gangland assassination of a member of a leading figure in Swedish organised crime by a rival group who carried out the shooting by firing 10 shots at point blank range in London in front of the victim’s wife and 2 year old child. This was a carefully planned operation involving protracted surveillance of the victim, disguises, the procurement of semi automatic weapons and ammunition and a clean up operation after the event.
Mark Heywood KC leading Gregory Fishwick defended in this multi-company boiler room fraud that sold diamonds as investments. The Crown’s case was that a team of brokers including Lewis Bloor from The Only Way is Essex used false identities and pressure sales techniques to con elderly and vulnerable people from hundreds of thousands.The evidence against them included a purported confession that was excluded upon application by the Defence. The Crown also sought to include companies either side of the Indictment period as evidence of bad character but this again was successfully resisted. The Defence managed to show that the Crown’s disclosure was fundamentally flawed. Having read the written submissions the Crown initially dispensed with their own expert who had valued the stones and nearly worthless. Having then considered the supplemental written submissions on disclosure the Crown had to concede that they could not continue to prosecute any and all of the Defendants. Instructed by Bark & Co.
Matk Heywood KC led the Prosecution and subsequent reference of sentence to Court of Appeal of defence contractor employed by BAe Systems who compiled records of highly secret operational information relating to a missile system currently in service with the UK armed forces and abroad and then travelled to Europe to send copies by email to multiple recipients. Extremely unusual conviction for an offence under section 1 of the Official Secrets Act 1911.
Mark Heywood KC defended in this £7 million carbon credit fraud listed for three months. Following extensive legal argument before the close of its case, the Crown, who relied in large part on evidence of the state of the carbon credit market at the relevant time, was forced to acknowledge that its expert fell well short of the standards required in legal proceedings and that there had been disclosure failings such that it was unfair to continue to try the defendants. This case hit the headlines after the alleged expert, Andrew Ager, was discredited leading to many other convictions to be looked into on alleged mis-selling of carbon credits.
Mark Heywood QC represented the Crown in this case involving the plot by two individuals to kill the Prime Minister. The plan was to detonate a bomb at the gates of Downing Street and then kill Theresa May with a knife or gun.
Mark Heywood QC and Jonathan Polnay acted for the Crown in the case of Theodore Johnson whom was sentenced to life with a minimum tariff of 26 years, increased on appeal against Unduly Lenient Sentence, to 30 years in March 2018. Johnson had been convicted previously for the manslaughters of his partners in 1981 and 1993. His third victim, Angela Best, was murdered with a claw hammer in her flat in North London in December 2016.
Mark Heywood QC acted for the Crown in this prosecution of a British man who was jailed for possession of an AK47 gun, receiving £2000 for the purposes of terrorism and membership of ISIS.
Mark Heywood QC prosecuted the case involving the horrific killings of the Eastenders actress Sian Blake and her two children, whom were murdered by the partner and father Arthur Simpson-Kent. The defendant was sentenced to a whole life tariff.
Mark Heywood QC along with Brian Altman QC represented the Crown before the Supreme Court on this leading authority regarding joint enterprise / transferred malice. The Supreme Court held, restoring Gnango's conviction for the murder of Magda Pniewska, that he was guilty of murder notwithstanding the fact that he had not fired the shot which killed Pniewska during the shoot out which led to her death, and that the fatal shot had been fired by his opponent in an attempt to kill him.
Mark Heywood QC leading Ben Temple for the Prosecution at first instance, the Court of Appeal and the House of Lords where David Perry QC was also instructed.
J was found to be in possession of an extensive library of religious, political, ideological, military and extreme Islamist material some of which had an express terrorist purpose, digitally stored on his laptop, I-Pod, telephone and numerous digital disks comprising several hundred hours of audio and video material and several thousand pages of documentation. J was charged with possessing articles for a purpose connected with terrorism, contrary to section 57(1) of the Terrorism Act 2000. J pleaded guilty to four counts contrary to section 58 of the Act. The Court of Appeal then handed down judgment in R. v. K [2008] EWCA Crim.185 on the point of reasonable excuse under section 58(3). J, having applied successfully to vacate his pleas, claiming erroneous legal advice in the light of R. v. K, re-entered not guilty pleas at a preparatory hearing in the course of which the Recorder of Birmingham, regarding himself bound by R. v. K, ruled on a question of law formulated by the Crown that, by reference to R. v. K, under section 58 where a reasonable excuse is raised the prosecution must prove a terrorist purpose.
Leave to appeal to the House of Lords was granted. The three certified questions raised substantial, complex issues. The concept of reasonable excuse had to be considered across numerous statutory contexts. The Crown’s appeals (G and J) were allowed and J, a year after he had first done so, pleaded guilty to four offences contrary to section 58.
Mark Heywood QC together with the then First Senior Treasury Counsel, acted for the Crown in this prosecution of the notorious Serial Killer Levi Bellfield for the murders of the 22 year old French Student Amelie Delagrange and the 19 year old woman Marsha McDonnell as well as the attempted murder of Kate Sheedy. In 2011 Bellfield was convicted of the murder of Milly Dowler and sentenced to a whole life tariff.
Mark Heywood QC along with Jonathan Laidlaw QC conducted the prosecution of 2 NHS Doctors for conspiracy to murder by planning car bomb attacks in 2007 at London's West End Tiger Tiger Nightclub and at the Glasgow International Airport.
Mark Heywood QC along with David Walters QC and Duncan Atkinson prosecuted the longest running Old Bailey trial which concerned the "Fertiliser Bomb Plot" and conspiracies to cause explosions throughout the U.K.
"Mark is a class act."
Chambers UK 2025 - Financial Crime
"Mark has a formidable reputation for being right, so people listen to him."
Chambers UK 2025 - Financial Crime
"Mark knows everything on the law and is very relaxed and straightforward in his style. His client care is impeccable and he is very clear, concise and direct in his advice."
Chambers UK 2025 - Financial Crime
"Mark is the Rolls-Royce of advocates and every word he utters carries great weight."
Chambers UK 2025
"He is a brilliant tactician and a fantastic leader. He is very easy to work with and fantastic in court, and that's a view that resonates around the bar."
Chambers UK 2025
"He is top drawer and one of the most respected and sought after silks in the country,"
Chambers UK 2025
"Whatever's thrown at him, he will deal with it impeccably."
Chambers UK 2025
"He knows everything on the law and is very straightforward in his style. His client care is impeccable and he is clear and concise in his advice."
Chambers UK 2025
"He's got a real knack for being able to spot how things will unfold and time it all to perfection."
Chambers UK 2025
"Mark is a doyen of the criminal fraud Bar – a devastatingly persuasive advocate who is charming and erudite in equal measure. Even in the most complex fraud cases, he has every detail at his fingertips."
Legal 500 Fraud 2025
"Mark is a devastatingly persuasive advocate who is charming and erudite in equal measure. He is so compelling it is often difficult to work out how he could possibly be wrong. Mark has effortless charm and intellectual gravity at the same time. He carries with him a weight of experience and knowledge which is almost impossible to challenge."
Legal 500 2025
"His tactical awareness is pretty exceptional. He makes sure that when it comes to the crunch, he's put all the things in place required to get a result."
Chambers UK 2024
‘Mark is a master advocate at the height of his powers. He is simply one of the best criminal advocates practicing at the Bar. He works incredibly hard to prepare cases whilst managing to make complex advocacy look effortless.'
Legal 500 2024
'Mark is undeniably one of the top advocates at the criminal Bar for fraud. His knowledge and experience is unparalleled and juries love his easy and charming delivery. He has an encyclopedic knowledge of statute and practice which he deploys with great care and tactical awareness.’
Legal 500 2024 - Financial Crime
"Mark is totally outstanding and in a league of his own when it comes to complex fraud cases. He is very intelligent and a great tactician."
Chambers UK 2023 - Financial Crime
"An outstanding advocate who is very bright and respected by all."
Chambers UK 2023
' Mark is a master tactician and a real class act. His advocacy is smooth and eloquent. Everyone in the room listens to him when he speaks.'
Legal 500 - 2023 [Financial Crime]
"He is a Rolls-Royce who purrs and just keeps going."
Chambers UK 2022
"Just incredible. He exudes self-assurance and authority in the courtroom and is an inspiring performer." "A real class advocate, he is always on top of his brief and a worthy opponent."
Chambers UK 2021
“A truly class act and one of the very best at the Criminal Bar.”
Chambers UK 2020
“He just has a way of reducing what are extremely complicated submissions into a really easy, digestible and understandable form. He is first-rate.”
Chambers UK 2020
"He is very easy to work with and fantastic in court, and that's a view that resonates around the bar."
Chambers UK 2025
"The consummate silk."
Chambers UK 2019
"You can't get better than Mark Heywood. He's a beautiful advocate with great strategic awareness, who is lovely to work with and a very charming man."
Chambers UK 2018
"One of the best lawyers, if not the best lawyer in the country."
Chambers UK 2017
"Breathtakingly intelligent and beautifully eloquent."
Legal 500 2016