There are tighter passport controls across the EU this summer, aimed at keeping track of suspected terrorists. A side effect is that police have been able to catch up with other wanted criminals.

Under new EU border regulations effective since early April 2017, identity checks are mandatory for everyone leaving and entering the EU's Schengen passport-free travel zone. Previously, checks of travelers to non-Schengen destinations were much less rigorous. The Schengen zone includes 22 EU states as well as Iceland, Liechtenstein, Norway and Switzerland. Ireland and Britain are not part of the zone.

Now border control officers can crosscheck passengers' documents against EU-wide security databases, like the Schengen Information System (SIS), Interpol and registers of wanted persons.

However, catching criminals on the run has been a side-effect of the tougher laws. The heightened security was put in place as a response to a series of terror attacks in Paris and Brussels that involved EU nationals drawn by the ideology of the "Islamic State" (IS) terrorist group.

Read more: Deutsche Welle