Since the creation of the EU in 1993, it has developed its competencies in the area of justice and home affairs; initially at an intergovernmental level and later by supranationalism. Accordingly, the Union has legislated in areas such as extradition, family law, asylum law, and criminal justice. Prohibitions against sexual and nationality discrimination have a long standing in the treaties. In more recent years, these have been supplemented by powers to legislate against discrimination based on race, religion, disability, age, and sexual orientation. By virtue of these powers, the EU has enacted legislation on sexual discrimination in the work-place, age discrimination, and racial discrimination.

The Union has also established agencies to co-ordinate police, prosecutorial and immigrations controls across the member states: Europol for co-operation of police forces, Eurojust for co-operation between prosecutors, and Frontex for co-operation between border control authorities. The EU also operates the Schengen Information System which provides a common database for police and immigration authorities. This co-operation had to particularly be developed with the advent of open borders through the Schengen Agreement and the associated cross border crime.

Source

https://en.wikipedia.org/wiki/European_Union#Legal_system_and_Justice (23.12.2019)