One of the more controversial subjects to come to light during the NSU murder trial is the level of cooperation and support that neo-Nazi informants and organizations receive 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. Reports exist that one undercover intelligence agent who harbored right-wing sympathies was at the site of one of the murders. The agent was known in the village where he grew up as "little Adolf" in his youth.