BERLIN — A 2000 firebomb targeting Russian Jewish immigrants at a Duesseldorf railway station.
A 2004 nail-bombing in a Cologne immigrant neighborhood.
A 2008 fire in a Ludwigshafen apartment building that killed nine Turkish immigrants, including five children.
All unsolved crimes, and all now reopened as suspected work of a small band of neo-Nazis who allegedly killed and terrorized minorities for a decade, undetected by Germany's thousands of security authorities nationwide before they tripped up this month.
Chancellor Angela Merkel has vowed a thorough investigation, calling the crimes "a disgrace, shameful for Germany."
Yet many questions remain.
Key among them is whether the group is responsible for deadly hate crimes beyond the 10 deaths for which they are blamed, and whether other members or sympathizers are still at large.
More broadly, the nation is asking how such a group could have been allowed to carry out these crimes undetected for so long.
The case has provoked widespread criticism that in an effort to focus on leftist and Islamic terrorism, authorities have been blind to the threat of the right.
"If this had happened in Turkey, if eight or nine Germans had been killed with the same weapon and if the murderers were not found, all European nations would be up in arms, they would declare Turkey to be a barbarian country not fit to live in," Elif Kubasik, whose husband, Mehmet, was killed in April 2006 in a slaying linked to the group, told Turkey's Sabah daily.
Other families of the nine known minority victims have come forward with tales of how police suspected organized crime, drugs or interethnic rivalries - anything but far-right violence.
Aside from one Greek, all of these victims were of Turkish origin, and the group took responsibility for their deaths in a homemade video. The group also is thought have carried out the 2007 shooting death of a German police officer.
Authorities now are scrambling to determine whether the group was linked to other violent crimes targeting immigrants.
In the amateur DVD, the group also appeared to take credit for a 2004 bombing in the Muelheim district of Cologne, home to many Turks, in which 22 people were injured.
The interior minister at the time, Otto Schily, said that attack was likely "not terrorists but the criminal underworld."
Investigators also are taking a new look at a July 27, 2000, explosion at a rail station in Duesseldorf that injured 10 recent immigrants from the former Soviet Union, six of them Jewish. They also have reopened the investigation of a blaze in 2008 in the southern city of Ludwigshafen, in which five children and four adults - all ethnic Turks - died.
"We have a growing scandal," Justice Minister Sabine Leutheusser-Schnarrenberger told the Sueddeutsche Zeitung. "Thirty-two state police and domestic security offices have not been able to stop a series of far-right extremist murders."
Ms. Leutheusser-Schnarrenberger and Interior Minister Hans-Peter Friedrich held a crisis meeting this month with representatives of the law enforcement agencies to try to figure out what went wrong, and where.
Although the emphasis is on solving the crimes, they also discussed restructuring Germany's complex web of police and security agencies - a decentralized system set up in a post-World War II attempt to avoid the repeat of the Nazis' absolute consolidation of power.
"Federal prosecutors have to focus on the crime and its perpetrators," Ms. Leutheusser-Schnarrenberger said. "Politicians have to answer the question of whether the security structures in Germany can work effectively and efficiently and what changes might be needed."
The story began to unfold on Nov. 4 with a brazen daylight bank heist in the central city of Eisenach, when two masked men wearing hooded sweat shirts reportedly made off with $94,360 and police tracked them to a parked mobile home.
As authorities closed in, the mobile home caught fire. After dousing the flames, they found the bodies of two men inside - Uwe Boehnhardt, 34, and Uwe Mundlos, 38 - both had been shot in the upper body in an apparent suicide committed before setting the vehicle ablaze.
Several hours later, another fire broke out in an apartment 110 miles to the east in Zwickau.
The two blazes seemed unrelated, until a pair of pistols were found that linked the two and blew the entire case up, leading authorities to tie the group to the killings of the nine minorities and the policewoman.
The policewoman's service weapon was among the charred ruins inside the mobile home. At the burned-out apartment, police found a Czech-made 7.65 mm Ceska pistol, known by authorities to be the weapon used in the slayings of the minorities.
Copies of a self-made propaganda DVD also found among the wreckage tipped police off to the group's name, the Nationalist Socialist Underground - a clear reference to the full name of the Nazis - the "National Socialist" party - and their extreme nationalist hatred.
The video features pictures of the victims from the Ceska-linked killings, and included a cartoon image of the Pink Panther standing next to a sign proclaiming "Germany Tour: 9 Turks shot." The minority victims were all small-business men, shot at close range in execution-style killings between 2000 and 2006.
Days after the two fires, 36-year-old Beate Zschaepe surrendered to police. She has since been charged with membership in a terrorist organization for allegedly co-founding the group with Boehnhardt and Mundlos and for starting the fire in an attempt to destroy evidence.
Though the same pistol was used in all of the killings of the minorities, police could find no other leads and they remained unresolved for years.