On Feb. 12, 2005, Sister Dorothy Stang, a 73-year-old Sister of Notre Dame de Namur and a Dayton, Ohio, native who had spent more than 30 years as a missionary in Brazil, was gunned down in that nation's Amazon rain forest.

The investigation and trial that followed are chronicled in the gripping documentary "They Killed Sister Dorothy," narrated by Martin Sheen and airing on the HBO2 pay service March 25, 8-9:30 p.m. (check local listings).

Filmmaker Daniel Junge uses interviews with Sister Dorothy's friends and co-workers to explain her efforts to establish the endangered area's first practical sustainable development project in collaboration with the Brazilian government. The Project for Sustainable Development model allows landless peasants to settle on 250-acre lots, and farm 20 percent of the land, leaving the remainder unspoiled.

While Sister Dorothy's work led admirers to nickname her the "angel of the Amazon," it also inspired intense opposition, principally from wealthy ranchers and loggers anxious to continue their exploitation of the region's natural resources.

While the gunman and an on-the-spot accomplice were quickly identified and arrested, the investigation would lead much further, with evidence eventually pointing to a conspiracy on the part of Vitalmiro Bastos de Moura, known as "Bida" --- whose property bordered that of the Project for Sustainable Development --- and another powerful landowner, Regivaldo Pereira Galvao, called "Taradao." (This second moniker, the script points out, translates as "Sleazy.")

The twists and turns of the legal process against these two make for intriguing and suspenseful real-life drama, as intimidated witnesses recant their testimony and booming defense attorney Americo Leal denounces Sister Dorothy as a violent agitator dispatched to Brazil by the FBI.

This courtroom struggle between vested interests and the powerless also raises profound, globally relevant moral issues about the future of the environment and the just distribution of wealth in the developing world. And, though the film is unabashedly one-sided, the sense of outrage underlying the narrative --- unmistakable despite Sheen's ever-smooth delivery --- is easy to share.

"They Killed Sister Dorothy" is rated TV-PG/V (parental guidance suggested; moderate violence).

---CNS John Mulderig is on the staff of the Office for Film & Broadcasting of the U.S. Conference of Catholic Bishops. More reviews are available online at www.usccb.org/movies.