Mariano Calleja Estellés graduated in Law from the Universidad Autónoma de Madrid in 1998 and has specialised in contentious-administrative procedural practice since 2000.

Currently a partner of Winkels Abogados, he was for 12 years Coordinator of the Municipal Legal Guidance Service for Foreigners of the Madrid Bar Association and for cases of racism, xenophobia, transphobia and homophobia.

With extensive experience in the criminal field, Mariano Calleja specialises in assisting victims of different types of crime, as well as defending them in court, with particular expertise in criminal proceedings arising from family law procedures, as well as in the field of gender violence crimes.

Thanks to his extensive professional experience, Mariano Calleja has taught, directed and coordinated numerous courses in organisations such as the Madrid City Council and the ICAM, related to the practice of law, attention to victims of crime and continuous training for the Public Defence Service (Turno de Oficio).

He is also an international consultant in the field of free justice, legal defence in legal proceedings for victims, protection of human rights, and implementation of systems to improve access to judicial systems, having participated in the improvement of this type of system in several countries and backed by extensive training both nationally and internationally.