Updated

A retired Colombian general has been found guilty and sentenced to 30 years in prison for his role in the 1989 assassination of a top presidential contender.

The murder of cartel-fighting politician Luis Carlos Galan marks one of the bloodiest chapters in Colombia's history, one depicted in the hit Netflix series "Narcos."

On Thursday, the Supreme Court ruled that Miguel Maza, who then headed Colombia's intelligence agency, paved the way for the murder by weakening Galan's security detail days before he was gunned down at a campaign rally.

Maza has been jailed since 2013 and says he himself was the target of cartel assassination plots.

The trial comes as Colombians re-examine the role of state agents in several high-profile killings during the apex of drug-fueled violence three decades ago.