Twelve months after revelations that a neo-Nazi trio was likely behind a seven-year murder spree targeting immigrants, Germany has sought to mend security flaws but the trauma still reverberates. Feelings of shock and anger ran deep in Germany, still haunted by its Nazi past, after details began to emerge on November 4 last year of the cold-blooded killings of nine men of Turkish and Greek origin and a policewoman between 2000 and 2007. With a Turkish community of around three million people, Germany was jolted into an all-out security reform, especially of its domestic intelligence service, which came under fire for a botched probe that led to top-flight resignations. Authorities have faced intense pressure to explain how the extremist gang was able to operate with impunity for 11 years and why they did not zero in on the far-right scene at an earlier stage. A possible ban of the neo-Nazi political party, the National Democratic Party of Germany, which has members in two eastern German regional parliaments, is again being considered after a failed 2003 attempt. But recriminations continue. Kenan Kolat, president of the Turkish Community of Germany, has said that one year on from the discovery of the extremist cell, he is \"very disappointed\" and \"bitter\" about the government\'s response. \"The political class doesn\'t want to recognise that there is an enormous problem of racism in Germany,\" he told reporters this week, saying more lessons needed to be drawn from the affair. He called for a broad social debate on what he termed \"institutional racism\". The neo-Nazi gang calling itself the National Socialist Underground (NSU) only came to light when two members, Uwe Boehnhardt, 34, and Uwe Mundlos, 38, were found dead in an apparent suicide pact and a now 37-year-old woman turned herself in. Beate Zschaepe is still being held in custody but has yet to be charged. Around 10 people are suspected of links to the trio, and investigators have tried to learn whether the insular group might have been part of a shadowy wider network of far-right militants. The head of a parliamentary commission of inquiry set up to shed light on the affair, Sebastian Edathy, has highlighted \"a mentality problem within the security services\", including the police, and suggested more rigorous recruitment of officials. The much-anticipated report by the commission is expected by the end of the year. Investigators initially suspected that criminal elements from the Turkish community were behind the rash of killings. Suspicion also fell on the victims\' relatives, a point Chancellor Angela Merkel called \"particularly tormenting\" at a memorial service in February. The killings were \"a disgrace for our country\", Merkel said, vowing to do everything possible to shed light on them and bring those responsible and their supporters to justice. In July, the head of the domestic intelligence agency, Heinz Fromm, stepped down after it emerged that the agency had destroyed files with information about the extremist group several days after the NSU came to light. \"We have to repair the security apparatus to restore confidence. Personnel changes will not be enough,\" Justice Minister Sabine Leutheusser-Schnarrenberger said, quoted Thursday by the Passauer Neue Presse daily. The scandal claimed two other top officials in quick succession -- the head of the secret service bureau in the eastern state of Saxony resigned, while the leader of Thuringia state\'s bureau was dismissed. \"We were promised a lot, also by Chancellor Merkel. Then we heard that files were destroyed and we have the feeling that we\'re not getting any closer to the bottom of this,\" Gamze Kubasik, whose father Mehmet was killed in 2006, told the Tagesspiegel daily on Friday. \"We feel deceived and I am angry and sad.\"