Criminal phenomena have had intensive repercussions on social life, they being registered rapidly an evolutive trend during the last period of time, including the last three years, related to the Covid-19 pandemic crisis. The criminality, as a general phenomenon, has permanently been in the authoritiesʼ attention, both at national and European level. They have been involved in finding solutions in purpose to diminish this phenomenon, as much as possible. Their actions regarding the control of criminal phenomena, particular attention being paid on the cases of illegal immigration, have been focused on the three main directions, such as prevention, control and sanction. In the current paper, the aspects on controlling criminality will be approached, with a special interest to the phenomenon in Southeast Europe, due to its transit specific feature to the Western European countries. The measures adopted by the authorities in order to discover any form of illegal immigration have been taken into account.