He joined the firm in 2015 and subsequently worked as Foreign Attorney in the White Collar Defence & Investigations practice of the New York office of Arnold & Porter Kaye Scholer LLP, taking part in the advice and defence of individuals and companies in investigations by the DOJ, SEC and NYAG, internal investigations at multinationals and extradition proceedings to the US.

His professional activity focuses mainly on the following practice areas:

Criminal litigation

León has extensive experience in the practice of criminal defence and private prosecution in all types of proceedings and at all instances before the main courts, with a particular focus on highly complex, multi-jurisdictional proceedings at the Spanish National Court, defending the interests of both individuals and legal entities in all types of matters, in particular:

• white-collar crimes and corporate offenses (fraud, malfeasance, frustration of foreclosure, forgery of documents)
• offenses against the public treasury (tax offenses, public subsidy fraud, money laundering)
• crimes against the administration (bribery, influence peddling, misappropriation)
• Intellectual and industrial property offenses (counterfeit, disclosure of secrets)
• offences related to IT and new technologies (cryptocurrency, NFTs)
• offences against the market and consumer (business corruption, insider trading, stock manipulation)
• environmental and urban planning crimes (damages to protected assets, emissions and effluents)
• offenses against workers’ rights (occupational accidents)

He provides advice in relation to international legal assistance procedures (letters rogatory, INTERPOL red notices, European arrest warrants) and is noted for his expertise in providing legal defence in extradition proceedings, representing both individuals and foreign states.

Internal investigations

León advises in the performance of internal investigations at multinationals, in a wide range of industry sectors, particularly in those with implications in multiple jurisdictions, and represents companies under investigation by national and international regulatory and governmental institutions (SEC, FCPA, UK Bribery Act) and provides legal assistance in the course of parliamentary investigations.

Criminal compliance

He participates in providing legal advice on regulatory compliance and on the design, implementation and update of organizational and crime prevention models for corporations, while also defending companies before the courts in connection with the criminal liability of legal entities.

León speaks Spanish and English and is fluent in Italian.

He serves as a member of Garrigues’ Equality Committee since 2020.

León also participates as a volunteer in teaching the Know your laws and Constitutional values for immigrants programs organized by the Immigrant Participation and Integration Centres (CEPI) of the Family, Youth and Social Policy Department of the Government of Madrid since 2016, as well as a mentor in the Comillas Alumni Mentoring Program at Universidad Pontificia Comillas.

• Double Degree in Law and Economics & Business Administration (E-3), Universidad Pontificia Comillas – ICADE (2014). Exchange program with Libera Università Guido Carli Roma (LUISS).
• Consumer Rights in the European Union. Alternative Dispute Resolutions and Collective Redress. European Union Lifelong Learning Programme, Università degli Studi di Udine (2014).
• Master’s Degree for Access to the Legal Profession - Business Law, Universidad Pontificia Comillas – ICADE (2015)
• Executive Program on the Impact of the Digital Revolution on the Legal Industry: Blockchain and Artificial Intelligence, Centro de Estudios Garrigues (2019).
• Bitcoin and Cryptocurrency Technologies, Princeton University (2023).
• An Introduction to American Law, Penn University (2023).
• Introduction to Key Constitutional Concepts and Supreme Court Cases, Penn University (2023).

• Professor of Legal Theory of Crime in the Dual Degree in Law and Business Administration and Management (E-3) since 2026 at Universidad Pontificia Comillas (ICADE), where he also collaborates in the teaching of Criminal Litigation in the Official Master's Degree in Access to the Legal Profession since 2016 and Introduction to Criminal Law and its sanctions in the Dual Degree Program in Law and International Relations (E-5) since 2023.
• Professor of Data Protection in Digital Environments and Cybersecurity: Cybercrime in the Master's Degree in Access to the Legal Profession and Master's Degree in Legaltech & Business Analytics, as well as in the Digital and Technology Law Program at the Garrigues Business & Law School.

• Member of the Madrid Bar Association (ICAM).
• Member of the Spanish Business Litigation Club (CEL).

Recognized by The Legal 500 as a Leading Associate in the White-collar crime category in Spain:

He has been invited as a speaker at conferences on innovation, such as the conference A Decade of PLN in Spanish organized by the Institute of Knowledge Engineering and IBM Innovation Studio, and has contributed to various articles on the challenges for companies arising from electronic evidence and the use of blockchain technology, the legal risks associated with operating in the metaverse, and the issuance and marketing of NFTs.