(CNN) -- A Brazilian rancher convicted of orchestrating the 2005 killing of an American nun has been acquitted after a witness contradicted his own testimony.
A jury voted 5-2 to dismiss Vitalmiro "Bida" Bastos de Moura's conviction on charges of ordering Sister Dorothy Stang's death, according to a statement from a court in the Para state capital of Belem.
"We'll continue to fight and hope for better results," said Stang's brother, David, who traveled to Brazil for the trial.
The murder of Stang -- gunned down along a muddy road in northern Brazil's rain forest -- was often seen as emblematic of the fierce struggle for land in the Amazon region.
The 73-year-old nun from Ohio worked for more than two decades in Anapu, in northern Brazil, helping poor farmers attain a sustainable living and protecting the rain forest from ranchers and loggers.
"They weren't so wrong in absolving him," Prosecutor Edson Augusto Cardoso de Souza said of Moura on Tuesday. The attorney was referring to the testimony from Amair Feijoli Cunha, who had said at an earlier trial that Moura had asked him to hire two gunmen to kill the gray-haired nun.
In this trial, Cunha, who is serving 18 years for his role in Stang's death, denied saying that, according to Cardoso.
"Amair [Cunha] said that Bida [Moura] hadn't had any role at all," Souza said.
The same jury upheld the conviction of Rayfran das Neves Sales, one of two gunmen who had confessed to shooting Stang, the court statement said. Sales was sentenced to 28 years in prison without the possibility of an appeal, the statement said.
The trial was Sales' third in the case. A court annulled his second conviction, citing technical problems, according the court in Belem.
Under Brazilian law, retrials are required for sentences that exceed 20 years.
The second gunman, Clodoaldo Carlos Batista, is serving 17 years, and a fifth man, Regivaldo Pereira Galvao, also accused of planning the murder, awaits trial.
The president of the Brazilian Bar Association said Wednesday in a statement on Moura's acquittal that the legal system was sending a "very bad" signal.
"One jury imposes the maximum sentence and the other completely absolves him," Cezar Britto said. "That difference can, and should, be corrected on appeal."
Leaders of the Sisters of Notre Dame de Namur, to which Stang belonged, expressed disappointment.
"With [Bida Moura's] release, justice has again been thwarted," Sister Camilla Burns, the congregational leader, said in a statement.
"Dorothy is our sister, so our grief is personal," she said.
Ohio Provincial Superior Sister Teresita Weind said in a statement, "We know that this decision will not end Sister Dorothy's work for the peasant farmers and their families in Brazil. ... All she ever wanted for them was dignity and the basic rights due children of God. No court decision can change this or dim her legacy."
Following Stang's death, the Brazilian government set aside more than 30,000 square miles of Amazonian land for protection.