Boris Nemtsov: Opposition figure who took on Vladimir Putin

{The only thing I have to say is, many things are happening whole around the world and all of this day by day will get worst, all we see right now are conspirations, war conflicts, economic conflicts, epidemics and other situations.}
-Cognitio Verum-

Outspoken critic of Putin shot and killed 02:35

(To read more information about this publication please visits CNN) The slaying of prominent Kremlin critic Boris Nemtsov in the heart of Moscow has shocked Russia and the wider world.

His murder, two days before a planned opposition march, has also outraged fellow opposition figures and prompted a slew of speculation over who could be behind it.

Some government critics pointed fingers in the direction of President Vladimir Putin or one of his supporters. State media reported Nemtsov had received threats linked to his stance on the Charlie Hebdo attack in Paris.

The Kremlin suggested Nemtsov may have been killed by enemies of Russia intent on creating political discord. The leader of Russia's Communist Party similarly blamed anti-Russian "provocation," according to the official news agency Tass.

So who was Boris Nemtsov? And how did he make so many enemies?