Italian fugitive Cesare Battisti, a former communist militant, was extradited to Italy after being arrested on Saturday, in the Bolivian city of Santa Cruz de la Sierra.
Officials confirmed that Battisti had been put on a plane and sent directly to his home country.
Battisti, 64, is wanted in Italy for killings he carried out as a member of the Armed Proletarians for Communism in the 1970s, for which he had been serving four life sentences.
But he escaped from jail in 1981 and — after brief stints in France and Mexico — settled in Brazil.
Italy nearly secured his extradition in 2010 but the leftist then-President Lula, thwarted the move by granting Battisti asylum on his last day in office.
However, Brazil's newly-elected far-right leader, Bolsonaro, who took office in January 1, had pledged to send him back to Italy, prompting Battisti to flee.
Bolsonaro's son and fellow politician, Eduardo, took to Twitter to announce the extradition, writing to Italian Interior Minister Matteo Salvini that "Brazil is no longer a land of bandits" and that a "little gift is coming."
'End in days in jail'
Salvini responded on facebook by thanking President Bolsonaro, Interpol and the other law enforcement agencies which tracked down Battisti.
He described the fugitive as a "delinquent who does not deserve a comfortable life on the beach, but to end his days in jail."
"My first thought today goes to the families of the victims of this killer," he added.
Italian President Guiseppe Conte also too to Facebook to remember the victims and announced that a place is en route to Bolivia, where it is scheduled to land at 17:00 CET.
"Waiting for him here are are jails so that he can atone the life sentences that the Italian courts have inflicted on him in past rulings, not becuse of his political ideas, but for the four crimes he committed and for the various crimes related to armed struggle and terrorism," he wrote.