The father of a classmate supposedly did business in Russia during the 1990s and, according to my classmate, witnessed an execution beneath a bridge somewhere in Moscow late in the evening. I don't remember a name of the bridge, and I can't verify whether the story was true. However, he was completely serious when telling it, and I do remember hearing media reports about organized crime killings and similar incidents in Russia during the chaotic post-Soviet years. So while I can't confirm this particular story, it doesn't sound impossible for that period.