One of the more controversial subjects to come to light during the NSU murder trial was the level of cooperation and support that neo-Nazi informants and organizations received from the Federal Office for Protection of the Constitution (BfV), Germany's domestic security agency. The BfV began cultivating informants from Germany's neo-Nazi groups in the early and mid-1990s to deal with the rise in anti-immigrant crime like the Rostock-Lichtenhagen riots of 1992. During the trial it became clear that BfV informants were aware or potentially aware of the homicides and other crimes attributed to the NSU and that this information was not shared with local police either accidentally or purposefully. All attempts made by the victims' legal team to examine this relationship have been buried by the prosecution team as irrelevant to the scope of the murder trial.