The world's longest-serving death row prisoner, Iwao Hakamata, won compensation from Japan this week after almost five decades in jail — and he owes his freedom to a judge with steely determination.

The former boxer, now 89, was exonerated last year of a 1966 quadruple murder after a tireless campaign by his sister and others.

But he might still be behind bars if not for Hiroaki Murayama, a judge who in 2014 dared do something extremely rare in Japan's often intractable legal system: order a retrial.