In May 2009, Mirko Heim joined the judicial service of the state of Baden-Württemberg. He initially worked as a public prosecutor in the youth division of the Karlsruhe public prosecutor’s office for around two years before working as a civil judge at the Bretten local court from 2011 to 2013. This was followed by a three-year secondment to the Ministry of Justice of Baden-Württemberg, where he was appointed personal advisor to the undersecretary in the personnel and organization department.

From 2016 to 2021, he served as deputy head of the department for combating organized crime at the Karlsruhe public prosecutor’s office and handled related cases. From 2019, he also was the press spokesperson for the Karlsruhe public prosecutor’s office. In 2021, he was seconded to the Karlsruhe attorney general’s office for nine months.

He then headed a general department of the Karlsruhe public prosecutor’s office – at the Pforzheim branch – for about two and a half years, where he was primarily responsible for handling capital cases.

Since May 1, 2024, Mirko Heim has been head of the department for combating organized cybercrime and darknet crime at the cybercrime center Baden-Württemberg, which was established at the Karlsruhe public prosecutor’s office, and also acts as press spokesperson for the cybercrime center.