BERLIN—On a rainy morning in a cemetery last month, Berlin’s hidden underworld briefly emerged from the shadows.
Nidal Rabih, one of the German capital’s most notorious criminals, had been killed by unidentified shooters days earlier, and his funeral drew nearly 2,000 mourners from across the country. Scores of police officers watched as bearded, beefy men in tracksuits and crew cuts filed by. Older men were ferried to the graveside in luxury cars with dark-tinted windows.
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