(RNS) A Brazilian rancher has been convicted of ordering the murder of U.S. nun Dorothy Stang and sentenced to 30 years in jail at his third trial on Monday (April 12).

The jury in Belem reached a decision late Monday after deliberating for 15 hours, according to a statement on the Web site of a state court. Vitalmiro Bastos de Moura had already been convicted and then acquitted of the murder of 73-year-old Stang. That decision was overturned on a technicality.

A native of Dayton, Ohio, Stang worked in the Amazon for 30 years to defend the rights of poor and landless peasants against large-scale farmers. Her work infuriated landowners and eventually led to her death in 2005.

Moura ordered the killing when Stang blocked him and another rancher from overtaking land the government had granted to farmers, The Associated Press reported. She was shot by hired gunmen in the town of Anapu.

Regivaldo Pereira Galvao, the other landowner involved in the murder, is scheduled to face trial at the end of the month. The two gunmen and a middleman have already been convicted in the trial.

“This conviction sends a strong message … that the impunity is ending,” Sister Rebecca Spires, who also works in the Amazon and knew Stang, told The Associated Press.

The 30-year sentence for de Moura is the maximum penalty in Brazil, a country with no death penalty.