Former school teacher Jacques Mungwarere was found not guilty Friday in Canada's second trial under the Crimes Against Humanity and War Crimes Act.
He was acquitted on one count of genocide by murder, and on one count of crimes against humanity by murder, after a 26-week trial by judge alone.
He claimed the accusations against him were fabricated. His lawyer said Mungwarere was fingered as a potential murderer three weeks after he agreed to testify for the defence at the trial of another Rwandan in the United States.
Judge Michel Charbonneau of the Ontario Superior Court ruled that the defence raised a reasonable doubt.
He said he struggled to believe witnesses for both the defence and the prosecution. Faced with those conflicting accounts, the verdict fell in Mungwarere's favour.
"You are free," the judge told the accused.
Mungwarere had been in custody since he was arrested in 2009 in Windsor, Ont., following an RCMP investigation that began in 2003.
He was accused of participating in a massacre of Tutsis in a hospital in the region of Kibuye.
Thousands of people had sought refuge in a local hospital, believing they might find sanctuary, but local militias encircled the compound and began shooting the people inside. Mungwarere was accused of shooting some of them himself.
His trial opened May 28, 2012, and ran to March 21 this year. It heard testimony from 44 witnesses, including Mungwarere.
Most of the Rwandan witnesses testified by video link from Kigali, Rwanda.
The only other prosecution under the war crimes law also dealt with Rwanda. In 2009, Desire Munyaneza was convicted in a Montreal court and sentenced to life in prison with no chance of parole for 25 years.
Leon Mugesera was deported last year to Rwanda to face charges.
In a 202-page ruling Friday, which was so long it took the judge an hour just to read the summary, Charbonneau did not blame the RCMP or the Crown for the way it collected evidence.
The case was undermined by signs that evidence was fabricated.
Defence lawyers proved that witnesses hostile to Mungwarere invented details of stories. Even the Crown conceded that certain evidence might have been false.
"This verdict demonstrates that the justice system works in Canada," said defence lawyer Marc Nerenberg.
The Crown has not decided whether to appeal Friday's verdict.
It has 30 days to decide on an appeal.