Kovalyov has been an outspoken critic of authoritarian tendencies in the administrations of Boris Yeltsin and Vladimir Putin . In 1996 , he resigned as head of Yeltsin 's presidential human rights commission , having published an open letter to Yeltsin , where Kovalyov accused the president of giving up democratic principles . In 2002 , he organized a public commission to investigate the 1999 Moscow apartment bombings ( the Kovalyov Commission ) , which was effectively paralyzed after one of its members , Sergei Yushenkov , was assassinated , another member , Yuri Shchekochikhin , allegedly poisoned with thallium , and its legal counsel and investigator , Mikhail Trepashkin , arrested
1999 Moscow apartment bombings
Russian apartment bombings
Sergei Kovalev