Javier holds a Law degree from the University of Salamanca and is a member of the judicial career, having served as a judge and magistrate in various courts and tribunals.

In 1990, he was appointed a member of the General Council of the Judiciary (Consejo General del Poder Judicial), where he served until 1996. In 2000, he voluntarily left the judicial career to pursue a career in legal practice.

He is the author of several legal works, including Code of Political Laws, Commentary on the Organic Law of the Judiciary, International Criminal Legislation, Commentary on the Penal Code, Legal Opinions, and Dictionary of Criminal Jurisprudence. He is frequently invited to contribute to media outlets and offers his views and insights on legal matters. He also regularly publishes articles and columns on current legal and social issues in various newspapers and magazines.