Buenos Aires, Argentina - On a narrow street in the heart of downtown Buenos Aires, just blocks from the city's most emblematic landmarks - the Obelisk, the Casa Rosada, the Congress - sits a neglected federal police station, the Intendencia of the federal police. Buses and small taxis whiz by, depositing soot on the rusting frame of the nine-story outpost at 1417 Moreno Street.

    Save the Argentine flag hanging from the second floor and a small police coat of arms above the entrance, the station looks the same as many other buildings crammed next to it frame against frame. Rusty old air-conditioners gasp for air, dirty tinted windows open to the little sun that penetrates the urban canopy. Boxy and functional, it was built long after Argentina had hopes of becoming a world power. It is a typical bureaucratic dump, constructed only with regard to the bottom line. It is where cases are filed to be forgotten.

    Here, thirty-two years ago, hiding behind the building's anonymity, the Argentine army and police maintained a clandestine torture center within walking distance of the centers of power. What transpired at the Intendencia is now at the center of a case that victims' lawyers are calling "the worst massacre in [Argentine] history."

    On June 12, Argentine federal prosecutor Felix Crous delivered his three-hour closing statement asking the three-judge tribunal to sentence Juan Lapuyole, Carlos Gallone and Miguel Timarchi - all active policemen at the time of the incident - to life in prison for the kidnapping and murder of thirty people. The incident, known as the Fatima massacre, took place in 1976, during the height of the Dirty War, during which Argentina's last military government "disappeared" around 15,000 people.

    The basic facts of the case are undisputed by the defendant's lawyers. Before dawn on August 20, 1976, thirty illegally detained and drugged prisoners from the Intendencia were forced into a truck and driven away from Buenos Aires up Route 8 beyond the outskirts of the city. About forty miles from the city, the prisoners were unloaded from the truck, blindfolded with their hands tied, and summarily executed. Each received a shot in the head from about three feet away. To dispose of the bodies, guards piled the dead prisoners over a charge of dynamite near the town of Fatima and blew them up. Body parts were found as far as 60 feet from the explosion.

    For over two decades, the suspected perpetrators of the incident were free from prosecution, saved by an amnesty law passed in the wake of democratic transition. But the amnesty was held unconstitutional by the Argentine Supreme Court in 2005, opening the way for prosecutors to indict Lapuyole, Gallone and Timarchi for the massacre. The Fatima case is the sixth to begin since the amnesty was overturned.

    The defendants have denied any involvement in the incident. Lapuyole, the highest ranking of the three, was a counter-intelligence officer at the time and claims to have had no knowledge of the detention center operating in the building in which he worked. Timarchi, injured by a grenade 10 months before, claims to have been on medical leave and not on active duty. Gallone admits to having worked at the Intendencia, but says he was with his father in Mar del Plata, a popular beach town five hours south of Buenos Aires, on the day of the incident.

    On May 7, Sgt. Armando Luchina, then a prison guard at the Intendencia (it was also functioning as a regular police station at the time) said he was "absolutely certain" to have seen all three men transferring "disappeared" prisoners into a truck on the night in question. Other prosecution witnesses - survivors of the center - claim to have been raped and tortured by Lapuyole and Gallone while prisoners at the center. One witness, held in the Intendencia, was handed a newspaper clipping of the Fatima massacre the day after a large group of prisoners had been "freed." He took it to be a sign of what would come if he did not cooperate.

    In three years of proceedings, Gallone announced just last week that he remembered he was in Mar del Plata on the day of the incident.

    Attacking the credibility of Lapuyole's alibi, Crous rhetorically asked, "What kind of counter-intelligence officer was he if he didn't even know there was a clandestine detention center operating in his own building?" which produced an uncomfortable chuckle from the public observing the case.

    Crous explained to the judges that the repressive apparatus of the military government was mired in secrecy. No documents exist outlining the structure of the secret "workgroups," as the small repressive intelligence units were called. It would not be impossible, therefore, for Timarchi to have been on medical leave but operating secretly as a member of a workgroup.

    All the men were officially in the chain of command of officers working at the Intendencia and carried decision-making authority.

    Crous began his accusation speaking slowly, accentuating each syllable of the names of the sixteen victims identified to date. About ten survivors of the center and families of the victims attended the proceedings and gripped one another as Crous read off the names of their friends and family. The onlookers were separated from the courtroom by a wall of bulletproof glass. A live audio feed accompanied the proceedings for the public to hear.

    Crous accused the men of putting their victims through "hell" before ordering them to their disturbing end, and pleaded for justice for these men's role in perpetrating a "systematic criminal enterprise."

    Between 1976 and 1983, Argentina was ruled by a military government, thrust to power amidst rampant political violence and runaway inflation. But once in power, the military unleashed violence on the Argentine population well beyond what was called for. In a repressive campaign known as the Dirty War, security forces from the Army, Navy and federal police "sucked up" around 15,000 victims. They were kidnapped, held blindfolded and incommunicado in clandestine prisons, tortured, and most were executed.

    When democracy returned to Argentina in 1983, then-President Raul AlfonsÌn made human rights prosecutions a centerpiece of his presidency. In 1985, five of the nine commanders of Argentina's ruling military governments were convicted in the historic trial of the junta. Three of the commanders were convicted - among hundreds of other incidents - for their role as co-authors of the Fatima homicides.

    In 1986 and 1987, under growing military unrest, the Alfonsin government was forced to pass amnesty laws and the prosecutions ended. The immediate authors of the crimes were never pursued.

    However, in 2001, eighteen years after the military government collapsed and 25 years after the worst of the repression ended, a lower federal court declared the amnesty laws unconstitutional. The laws were similarly revoked by Congress in 2003 after President Nestor Kirchner assumed office. The Supreme Court settled the matter once and for all in 2005, declaring the amnesty laws unconstitutional. Since this time, Argentina has reopened over 400 cases for repression committed during the Dirty War.

    Of the six cases to reach oral trial since 2005, all have ended in guilty verdicts. Amid the tremendous backlog of cases, the most legally certain cases have been the first to arrive in court.

    Time has taken its toll on the case. Of the 10 people suspected of ordering the massacre, Lapuyole, Gallone and Timarchi are the only ones still alive. Lapuyole, 78, is wheelchair-bound. If convicted, he will not go to prison. Rather, as is practice in Argentina, convicts over 70 years of age are placed under house arrest. The other two accused are in their early 60's, among the youngest of all the accused in the country.

    The defense will present its closing statements between June 24 and June 26. A verdict is expected in early July.