Putin critic Alexei Navalny thinks there's a 50/50 chance he'll be killed

Russia's main opposition figure thinks there's a 50 percent chance he will end up dead for speaking out against President Vladimir Putin, a fate that has befallen many of the Kremlin's enemies in recent years.

Alexei Navalny, 41, is Russia's most outspoken critic of the Putin regime, and is campaigning to challenge Putin in Russia's presidential election in 2018, even though he is officially barred from the ballot. 

Correspondent Ryan Chilcote spent a week with Navalny for the second episode of "CBSN: On Assignment," ahead of mass protests in June against government corruption.

Thousands of young people took to the streets in cities across Russia, with protesters marching through Moscow carrying signs that read "Navalny 2018" and chanting "Putin is a crook."

A lawyer by training, Navalny has been convicted three times over the past five years as his anti-corruption campaign has attracted the wrath of the Kremlin. Both he and his brother Oleg were convicted of embezzlement in 2014 and sentenced to 3.5 years in prison.  cbsnews.com