Germany on Wednesday launched a national database that should make it easier for law enforcement agencies to track potentially violent neo-Nazis, replacing a system that had all but blocked different state and federal authorities from sharing information.

The long-standing lack of information sharing created a major gap that prevented police from capturing a cell of rightist killers who only came to nationwide attention when two of them died in an apparent murder-suicide.

That, despite the fact that the trio of neo-Nazis - who adopted false identities and are alleged to have killed nine immigrants and a policewoman between 2000 and 2007 - had been on the radar of at least some police departments over the years. Police only linked the group to the murders in 2011.

Surveillance has been handicapped by the fact that each of Germany's 16 states has both a police special branch and an anti-subversion agency.