Even EU citizens subject to a European arrest warrant or that are wanted internationally were able to travel freely, leaving or entering the continent "without being detected due to the non-systematic check of EU citizens," the report says.
"This raises the question of whether more can be done to enhance security within the Schengen area. This could include action to enhance police checks in internal border regions and along main transport routes," the report states, as quoted by the newspaper.
According to the report, among the common elements between all the recent terrorist attacks in the European Union are such facts as the appearance of many of the suspects on surveillance and national watch lists, and being subject to Schengen information system alerts. Many of the perpetrators and people involved with the terrorist attacks already had "petty" criminal records, the report adds.
"Should an obligation for information sharing be introduced for all existing EU security databases? Should those databases be searchable by biometric as well as alphanumeric data?" the report questions.
In December 2016, Anis Amri, a 24-year-old Tunisian national and a failed asylum seeker in Italy, drove a stolen truck into a crowd at a Berlin Christmas market, killing 12 and injuring 48 people. Amri left Italy and entered Germany through Switzerland, despite being a suspected terrorist.
On March 22, 2016, several bombs exploded at the airport and in a metro station in Brussels, leaving over 30 people dead and more than 300 injured. On Wednesday, the European Parliament is scheduled to debate a security resolution ahead of the one year anniversary of the Brussels attack.