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Most of the victims were immigrants and their deaths at first failed to make headlines. Police were quick to blame the slayings on foreign gangs with links to gambling and drugs.

But revelations that a string of unsolved killings may have been a cold-blooded neo-Nazi campaign against ethnic Turks shook the nation, forcing Germans to confront painful truths about racism and the broader treatment of immigrants in a society deeply conscious of the legacy of the Holocaust.

The sole survivor of the group blamed for the killings — the self-styled National Socialist Underground — goes on trial Monday in Munich, along with four men alleged to have helped the killers in various ways.

Beate Zschaepe, 38, is charged with complicity in the murder of eight Turks, a Greek and a policewoman. She is also accused of involvement in at least two bombings and 15 bank robberies carried out by her alleged accomplices Uwe Mundlos and Uwe Boenhardt, who died in an apparent murder-suicide two years ago.

Zschaepe, who surrendered to police four days after Mundlos and Boenhardt died, denies the charges. If convicted she faces life imprisonment.

The case is being closely watched by Germany's 3 million ethnic Turks, many of whom feel marginalized by German society despite having lived in this country for decades or even being born here.

"There have been only a handful of trials in recent German history that have had a similar effect," said Gurcan Daimaguler, a Berlin lawyer of Turkish origin who represents some of the victims' families. He cited court cases against members of the far-left Red Army Faction terror group starting in the 1970s and the trials of East German border guards who fired at people trying to flee to West Germany during the Cold War.

"These were all trials that went beyond the courtroom," Daimaguler told The Associated Press in a recent interview. He noted that each of them prompted periods of soul-searching that in some cases continue until today.

It was only when Mundlos and Boenhardt died following a botched bank robbery in November 2011 and weapons were found at the scene tying them to the killings that authorities acknowledged they had failed to stop what amounted to a far-right terror campaign that lasted more than a decade.

Public debate has focused on how Germany's well-funded security services could have been so catastrophically wrong with their long-held theory that the killings were the work of immigrant criminal gangs.

Several high-ranking security officials including the head of Germany's domestic spy service have already resigned over blunders made during their watches. These ranged from failing to act on intelligence about the trio's whereabouts in 1998, shortly after they avoided arrest on lesser crimes; shredding evidence gathered by informants close to the group; and ignoring a racist motive in the crimes despite the fact that random killings without claims of responsibility fit the pattern recommended for decades by racist supremacists.

For years the media described the killings as "Doener Murders," after the popular Turkish dish of spit-roast meat served in snack bars across Germany. Yet only two of the nine men killed worked in doener restaurants, and many Turks say the phrase reflected the dismissive attitude which mainstream society had toward the victims.

The police failures prompted Parliament to establish an independent panel investigating whether there was institutional reluctance to deal with far-right extremists.

Its chairman, Sebastian Edathy, has said that not only did Germany's 36 security services fail to exchange information in the case, but the potential for far-right violence was massively underestimated even as some officers instinctively blamed the victims.

An internal document drawn up in 2007 by police in the southern state of Baden-Wuerttemberg and obtained by The Associated Press asserted that the likely killer couldn't have come from Western Europe because "in our culture the killing of human beings is a grave taboo" — a striking comment in a country that made genocide against Europe's Jews a matter of state policy in the last century.

Zschaepe, Mundlos and Boehnhardt met as teenagers in the eastern city of Jena amid an ideological vacuum following the 1989 collapse of the Socialist dictatorship in East Germany.

The region suffered economically during the early 1990s. Anti-immigrant sentiments were voiced openly even by mainstream politicians, providing a fertile recruiting ground for far-right groups.

Thomas Grund, a social worker in Jena who knew the trio when they first showed up at his youth club 20 years ago, said Zschaepe showed no hint of political extremism until she befriended the two young men who, he said, would later become her lovers.

Grund says social workers warned throughout the 1990s that extremist groups were setting up base in small towns and villages in the region but authorities did little.

Sometimes, he says, it appeared as if officials were protecting the far-right.

Such claims have been made across the political spectrum, by people skeptical that a group such as the National Socialist Underground could manage for more than a decade to slip through Germany's sophisticated surveillance net for neo-Nazi activity. A parliamentary committee has uncovered several instances where security services appeared to hide what they knew about the group. Whether they were simply trying to cover up their own failures, protect their informers, or actually protect the group has been a matter of intense debate.

At a memorial event last year German Chancellor Angela Merkel apologized to the victims and their families for the wrongful suspicions that swirled around them. Police spent a great deal of time probing the victims' backgrounds and business dealings, suspecting them or those close to them of being involved in the drug trade and other illegal activity.

Merkel also pledged to take all necessary steps to help those affected by the crimes.

Her apology was well received by many Turks at the time. But some noted that she didn't spell out that most of the victims were targeted because they were different from mainstream society: Turkish and Muslim.

"Here in Germany we are scared of using the word racism," said Daimaguler, the lawyer. "As long as we don't call it what it is we will never be able to solve the problem."

The authorities' reluctance to highlight the xenophobic motive also worries Barbara John, the official intermediary between the victims' families and the government.

She is currently campaigning for memorial plaques to honor the victims and highlight the racist nature of the crimes.

John, a longtime campaigner on immigration issues, said this would go some way toward giving the victims' families a sense that they are being taken seriously by the authorities.

"German society as such isn't racist, but there is a deep-rooted lack of trust toward the immigrant community," she said, noting that it was only recently the families started receiving financial compensation from the government.