The controversial Argentine activist Milagro Sala was acquitted Thursday of charges of attempted murder.
The decision by Jujuy province's Criminal Court 2 "is a small glimpse of hope that justice is being served despite the political persecution that many of our comrades are suffering", Sala told reporters, as she was escorted back to house arrest.
"I was not expecting, it is a huge surprise", she added.
Sala, the leader of the Tupac Amaru activist organisation, stood accused of ordering the failed assassination in 2007 of an alleged political enemy, Alberto Cardozo.
Sala's alleged associate Fabián Avila was sentenced to six years and six months in prison as the mastermind of the plan to kill Cardozo.
Avila and Cardozo faced off in a shoot up in front of a Jujuy butcher's shop on October 27, 2007. One of the bullets hit an 11-year-old bystander who was treated in hospital for serious gunshot wounds.
Cardozo was also acquitted of charges of attempted murder on Thursday, after three years under preventative arrest.
Sala faces several charges in Jujuy province, where she has been detained since January 16, 2016.
In December 2017, the Supreme Court ordered her release into house arrest following a petition from the Inter-American Commission on Human Rights (IACHR). The IACHR, Amnesty International and a United Nations (UN) expert committee on human rights had determined her arrest was arbitrary.
In a separate trial, prosecutors are demanding Sala spend 22 years behind bars for the alleged of embezzlement of US$1.5 million (60 million pesos) in national funds for housing projects. She also faces a three-year prison sentence for a demonstration she led against Governor Gerardo Morales.