Piers Mostyn

Year of Call: 1989

Piers practises in the most serious and complex areas of criminal defence, including homicide, fraud, serious violence, controlled drugs and sexual offences. He has been instructed as leading counsel in cases up to, and including, murder on numerous occasions.


To get in touch:​ Or you can contact the relevant​ Practice Team Clerks directly and they will be happy to assist with your enquiry.

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Legal 500 2023: Leading Junior

Criminal Defence


Piers is a senior junior, previously member of Tooks Chambers (Michael Mansfield's previous set). His practice is based on the full range of criminal defence - but particularly focussed on gang, violence and firearms offences. He has led on many occasions.

Notable Cases

Past notable cases can be viewed below. Click here to see a list of recent notable cases.


R v O and another
Two 15-year-olds accused of attempted murder on the platform of a railway station in North London. The victim was one of a gang chasing them who was stabbed in the stomach in the encounter.

R v Salau and others
Attempted murder case in which the victim was shot in the back in an underground station as he fled a gang.

R v Rhodes-Butler and others
Leading counsel in five-handed murder, concerning a "shoot out" in which dozens of bullets were fired.

R v Campbell and others
Leading counsel for alleged gunman in three-month murder with a firearm trial. Cut-throat defence and numerous legal arguments.

R v Mahorn and others
Leading counsel for up-and-coming rap star accused of shooting a local rival in a machine gun attack.

R v Blackwood
Leading counsel in murder with a firearm trial. Defendant acquitted on the basis of a substantial legal argument concerning Crown's reliance on hearsay.

R v Ross
Leading counsel in murder trial and re-trial involving the kicking to death of a vulnerable young man on a railway platform. Complex issues regarding causation involved detailed cross-examination of pathologist due to pre-existing ill-health of victim.

Serious Violence

R v Maclaren
Allegation of aggravated burglary in which cocaine addict suffering from psychotic delusions climbed into first floor window of residential house at 2 am and stabbed resident who confronted him

R v Osei
Kidnap and wounding with intent allegation in which two crack addicts were said to have attacked complainant in street and bundled him in to car. He was found seriously injured with fractures and memory loss 36 hours later.

R v Francis
Allegation of GBH with intent against young man stopped for drug search is alleged to have headbutted police officer, pushed him to the ground and then bit a portion of his ear off.

R v Awad
Allegation of violent disorder against anti-fascist involved in counter-demonstration against far-right mobilisation in Dover - a prolonged and violent stand-off over several hours resulting in serious injuries and multiple arrests

R v Qureshi
Violent disorder that was originally charged as murder. Allegation of confrontation between groups of young men on residential street in West London in which 3 or 4 very large knives were brought to the scene resulting in one fatality and the defendant suffering a serious stabbing injury.

R v N-D
Two defendants alleged to have tricked their way into flat of Knightsbridge-based sex workers, tied them up and robbed them at gunpoint. Defence case was that this was an agreed arrangement, a role-playing sexual encounter in which the defendants were to be tied up. They changed their minds on finding out that one of the complainants was transgender but were refused their money back. Aggravated burglary.

R v Ejiofor
Allegation of conspiracy to transfer firearm in gang-linked case involving the transportation of a firearm across London.

R v Mayers and others
Second on indictment in conspiracy to rob and possess a firearm with intent to cause fear. The defendant was alleged to be one of a gang of 20 to 30 masked men with firearms, bats and iron bars that attacked a Kent caravan site. The resident families were said to have a background of involvement in firearms and class A drug supply.

R v Ullah and others
Conspiracy to blackmail allegation. A bar/restaurant in North London was systematically smashed up by a large group of masked men with iron bars and bats. The owner and this family were then repeatedly threatened that if they didn't pay money they would face further consequences. This defendant was said to be the "inside man", using his friendship with the family to assist the conspiracy.

R v Adeleye and another
Representing a prize-winning young boxer accused, with his brother, of wounding with intent against a student following a night out. The victim's head injuries were so severe that he required significant hospitalization and suffered long term neurological damage.

R v Abdul
Allegation of involvement in the armed robbery of a cash-in-transit van.

R v Nelson and others
Accusation of possessing a firearm with intent to endanger life and assisting an offender arising from the shooting of a Police Community Support Officer following serious inter-gang violence in Hackney and the hiding of a machine gun in the loft area of the local estate.

R v Minott and others
Leading counsel for first defendant in a six-week, five-handed, conspiracy to supply firearms trial. The case concerned an arms factory, the importation of machine guns and pistols and a shooting feud within a north London gang.

R v Hussain
Allegation involving an apparently motiveless stabbing with a three-foot knife-like samurai sword in the street, causing serious intestinal injuries and severing the tendons to the fingers.

R v Gilmour
Wounding with intent allegation in prison, involving slashing of throat with improvised weapon involving razor blades.

R v Laurencin and others
Leading counsel for first defendant concerning a gang-linked aggravated burglary involving three loaded firearms. Complex legal arguments lasting several weeks concerning hearsay, bad character evidence and disclosure.

R v Morse
Representing a 72-year-old man facing bomb hoax allegations.

R v Rhodes-Butler
Possession of a firearm with intent, acquitted at half time following extensive cross-examination of experts and legal submissions concerning DNA evidence.

R v Anthony
Wounding with intent by glassing by student during celebrations after his final exam.

R v Fry and others
Aggravated burglary involving a group of males in balaclavas with baseball bats and other weapons engaging in a revenge attack on a family.

R v Singh
Attempting to cause grievous bodily harm to a police officer.

R v Rhodes-Butler
Aggravated burglary with a firearm.

R v Smith
Wounding with intent of a police officer in which the defence case was police witnesses were racist liars and that the defendant was acting in self-defence.

Controlled Drugs

R v Hutchinson
Defendant caught in a police sting trying to purchase a firearm and alleged to be supplying class A drugs on the dark web.

R v Obazi
Woman accused of importing 1 kg of cocaine by swallowing a large number of small packages and then refusing to defecate for a week after being detained at customs entering the UK. Defence of duress.

R v Brown
Possession of a loaded firearm with intent and a substantial quantity of class A drugs in a house said to be a drugs factory.

R v Pratt
Possession of a significant quantity of class A drugs with intent to supply. Lead witness for the Crown was a former suspect who gave evidence under the terms of a SOCPA contract.

R v Clifford
Quartermaster of the Wessex Hell's Angels in an allegation of possessing a substantial quantity of class A drugs with intent to supply.

R v Dacosta and another
Alleged possession of 1kg of cocaine with intent to supply and £50,000 of laundered cash.

Sexual Offences

R v Gillings
Represented defendant in three separate cases over four years on allegations that he raped vulnerable women, all involved substantial arguments concerning third party disclosure procedures and bad character (based on history of sexual offending and unproven allegations).

R v Oudahar
Allegation of multiple rapes and beatings over the course of several years against the defendant's partner with whom he was living. There were mental health issues involved and prior to being instructed in this trial, there had been five previous legal teams (all of them sacked) and the case had been listed for trial four times.

R v S
Teacher who ran a school from his home assisting students out of school hours, accused of indecent assault against a female child pupil. Third party disclosure issues concerning her social service, counselling and school records were central to the case.

R v Johnson and another
Client was a serving soldier in the Household Cavalry, who's work included guarding Buckingham Palace. He and a colleague were accused of rape and sexual assault against a highly intoxicated female student they had met at a nightclub local to their barracks.

R v B
Representing a young man with significant learning difficulties, requiring the assistance of an intermediary at trial, who was accused of sexual assault on a child.

R v Marina
Defendant accused of raping and wounding with intent against 60-year-old stranger after following her from the pub they were both drinking in.

R v Mytton
Historic child sex abuse allegation against a 69-year-old Church of England organist and choirmaster.

R v Head
Private instruction regarding child sexual abuse by grandfather on 9-year old grandchild.

R v Ashford
Historic multiple rape and other sexual offences committed against a child over the course of a year by a male in early adolescence. Defendant intermediary granted due to ADHD-related issues

R v Musa and another
Multi-defendant rape of a highly intoxicated young woman after they met at a nightclub.

R v Cheer
Multiple rape of a vulnerable, 13-year-old, girl, who had run away from home. Prosecution case collapsed following extensive legal arguments concerning the credibility and reliability of the complainant.

R v Tamscuic
Appointed by the court to cross-examine the complainant in relation to alleged sexual offences where the defendant acting in person.

Contact Piers

Financial Crime and Confiscation

Past notable cases can be viewed below. Click here to see a list of recent notable cases.


R v Rahman and others
Large-scale benefit fraud conspiracy worth hundreds of thousands of pounds. The defendant and others were said to have set up fake companies in order to facilitate dozens of claimants falsely claiming entitlement to credits. Defence centred on detailed cross-examination of prosecution forensic accountant.

R v Yildiz and others
Fraud conspiracy involving an allegation of staging multiple "crash for cash" incidents on motorways, involving innocent bystander drivers.

R v Ashraf
Defendant was a single mother employed as financial director at Gatwick Airport car parks who was accused of syphoning off hundreds of thousands of pounds over several years. The case against her involved detailed tracing of long term financial flows over multiple accounts by a forensic accountant.

R v Maughan and others
Allegation of conspiracy to steal power tools across a wide area of Hampshire and Surrey by a team from East London employing sophisticated counter-surveillance techniques.

R v Cooper
Defendant was alleged to have stolen a painting by Rolling Stones guitarist Ronnie Wood from the West End gallery where it was on sale.

R v Haider and others
Large-scale immigration fraud allegation involving the creation of fake jobs in order to satisfy visa requirements.

R v Ogunkeye
Multiple theft of postal packets by Royal Mail employee.

R v A
11-count indictment alleging that a young woman with mental health problems made false rape allegations against her boyfriend and uncle and also systematically defrauded her boyfriend, best friend and others of approximately £100,000 by falsely claiming to have medical and legal needs.

R v Caffell and others
Leading counsel in allegation of conspiracy centring on multiple fraudulent mortgage applications made by a property developer with assistance from a solicitor and others.

R v Rhoden and others
Leading counsel representing a DVLA employee in a conspiracy to defraud trial concerning processing forged and fraudulent licence applications for vehicles imported on forged documentation and stolen vehicles.

R v Begum
Multiple allegations of fraud by a young woman posing as a police officer and claiming to obtain legal assistance for people.

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Notable Cases & News

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  • BSC (Hons) Philosophy with Social History
  • Dip Law


  • French
  • German (basic)

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