Quincy has  appeared in many  High Court challenges concerning the  compatibility of criminal  law and procedure with  Human Rights Law by way of Judicial Review and Case Stated applications.  She successfully challenged the legality of an amendment to the Wildlife & Countryside Act 1981 which was conceded to be unlawful in R(Dodsworth) v DEFRA & CPS.

She  has  extensive experience of Prison  Law over 20 years and  has  acted for prisoners in a wide range of judicial review proceedings, including challenges to parole proceedings, security classification, oral  hearings for Category A prisoners, eligibility for Release on Temporary Licence, denial  of medical treatment and other challenges to conditions & facilities, discrimination  and  access to visits  and lawyers, and in private law claims involving  assault, negligence, misfeasance in public  office, discrimination (disability, racial, gender and sexuality) and under the  Human  Rights Act.

Successful cases include  R (MP)  v Secretary of  State for  Justice [2012] EWHC 214 holding that the Secretary of State’s interpretation of his policy on eligibility for Childcare Resettlement Leave for prisoners who are sole carers of children was  unlawful, that Article 8 was engaged by the decision and that the interests of the children must be taken into account, R (Longmire) v Secretary of State for Justice [2011] EWHC 1488 concerning oral hearings in categorisation review for Category A prisoners, R (Kebilene) v Secretary of  State for Justice concerning the legality of holding an administrative detainee in Category A conditions at HMP Belmarsh, R (Khan) v Secretary of  State for Justice where the  unlawfulness of the then existing policy  on calculation of eligibility for release on temporary licence for prisoners serving a default term was conceded and  R v Pitchfork [2009] EWCA Crim 1231concerning tariff reduction for exceptional progress. 

Quincy has an extensive civil practice in all aspects of police  misconduct and public law policing issues (in particular involving civil liberties and the right to protest), detention issues, victims of trafficking and police retention of and misuse of personal data (including cases arising from Operation Elveden). She  has successfully acted for Claimants in actions against the  police  and  prison  authorities for false imprisonment  and  malicious prosecution, assault, negligence, misfeasance in public office, discrimination issues (racial, disability, gender and sexuality) under the Equality Act, and other human rights claims under the Human Rights Act and for victims of trafficking and immigration detainees in claims against the Home Office.  

Quincy has  advised in numerous cases involving data protection, principally within the Criminal Justice context but also in relation to cases arising from Operation Elveden (sale  of private information by corrupt police officers to newspapers) and misuse of private information by other state and  private bodies. Within the criminal justice context Quincy has acted in judicial review and private law proceedings  concerning liability of the police, judicial and prison  authorities for inaccurate data  held on the PNC, court and prison records; inaccurate disclosure by police to Social Services and  liability of Local Authorities for disclosure of a juvenile’s criminal convictions within their care raising the interplay of the DPA and duties under the Children’s Act. She has also acted in numerous judicial review proceedings for prisoners concerning issues of security categorisation and involving subject access disclosure and in many cases involving Enhanced CRC disclosure to employers.

In related areas of judicial review in which she practises, information obtained through use of the Freedom of Information Act has been decisive; in one case tailored FOI requests demonstrated that a criminal offence created by secondary legislation had  been enacted in  error   leading to the Regulations being quashed.

She co-authored (with Keir Starmer QC) ‘Criminal Justice, Police Powers & Human Rights’ and was responsible for writing the chapters on  the collection and retention of personal  data, surveillance, the investigation of electronic data  and the interception of communications.

Quincy has appeared as Defence Counsel before the Special Court  for  Sierra Leone and  the International Criminal Tribunal for  the Former Yugoslavia, where she was also  briefed to act  as an amicus to the Appeal Chamber. She has a particular interest in transitional justice in post-conflict societies and  has worked for DFiD as a Senior criminal  justice consultant in Kosovo as well as conducting Human Rights Law training and seminars for government departments and senior police officers in the UK and judges,lawyers and prison officials in Sierra  Leone,  Botswana, Cameroon and Turkey. 

She  has an in-depth knowledge and working  experience of Caribbean constitutional law  with  a particular emphasis on the death penalty and has appeared in many of the leading cases in this area at the Privy Council ( Thomas  &  Hilaire  v  AG Trinidad  &  Tobago [2000]  2  A.C.  1    - unconstitutional to  execute prisoner while he has an outstanding application to an International Human Rights body  , Neville Lewis v AG Jamaica [2001]  2 A.C. 50   - prerogative of mercy subject to natural justice - allegations of unconstitutional mistreatment must be determined with oral evidence; all proceedings to be concluded within 5 years or else execution violates constitutional prohibition on inhuman and  degrading treatment) as well as having worked  for 6 months in Trinidad on behalf  of death row inmates.

Quincy has successfully acted in many criminal cases involving  political  protest, including the Greenpeace activists who were acquitted of causing criminal  damage to Kingsnorth power station (R v Hall  & Others) and  those acquitted of public nuisance for boarding a tanker laden with GM animal feed (R v Ayliffe & Others) and anti-war protesters acquitted of causing criminal  damage to B52 bombers at RAF Fairford (R v Olditch & Pritchard).