December 17, 2012 was the day Brazil’s Supreme Federal Court, known as the STF, concluded its plenary trial in Criminal Action 470, or AP 470, after 53 sessions. The case, widely known in Brazil as the mensalão case, involved 38 defendants and was, at the time, the court’s longest trial.

The proceedings began on August 2, 2012. They involved high-ranking political and financial figures and allegations assessed across several criminal offenses, including corruption, money laundering and embezzlement. The STF’s decisions were not uniform across the defendants or the charges: outcomes depended on the evidence and legal findings for each person and count.

What happened

The court’s judgment was published on April 22, 2013. It recorded 25 defendants convicted and 12 acquitted. Proceedings involving Carlos Alberto Quaglia were annulled and transferred to a lower court.

Those figures describe the judgment as published after the 2012 trial, rather than an unchanged final outcome for every allegation. The court reached both convictions and acquittals in the case. Some acquittals reflected findings of insufficient proof; others followed tied votes, when the court applied the presumption of innocence in favor of defendants.

That distinction is central to understanding AP 470. A defendant’s result could differ according to the alleged offense, and the overall totals should not be read as meaning that every defendant was convicted or acquitted of every charge considered by the court.

Why it matters

AP 470 remains a significant episode in Brazil’s legal and political history because the country’s highest court conducted an extended plenary examination of allegations involving prominent political and financial figures. Its 53 sessions illustrate the scale and complexity of the proceedings.

It also shows why legal outcomes require procedural precision. The end of the 2012 plenary trial did not mean that every part of the case was permanently settled in its original form. Appeals later altered specific results.

The bigger picture

The case provides an example of the different safeguards that operate in criminal proceedings at Brazil’s highest court. The STF issued convictions where it found the legal requirements met, but also acquitted defendants where proof was insufficient or where a tied vote required the result to favor the defendant.

Those acquittals were part of the court’s judgment, not exceptions outside the process. They underline that AP 470 was a collection of individual decisions on particular accusations, rather than a single finding applicable equally to all defendants.

The later appeal rulings add a further caution. In February 2014, the STF overturned the convictions of eight defendants for the offense then called formação de quadrilha, broadly referring to criminal association. The reversal changed part of the initial judgment and demonstrates why descriptions of the December 2012 result must identify it as the initial disposition rather than present it as an unmodified final outcome.

By the numbers

What happened next

Appeals continued after the initial judgment, producing changes on specific counts. The 2014 decision concerning the eight formação de quadrilha convictions is the clearest example in the record provided.

For readers assessing AP 470 today, the relevant historical point is therefore twofold: the STF concluded its unusually long trial on December 17, 2012, and the judgment that followed contained both convictions and acquittals. But subsequent appellate decisions mean the initial totals and individual findings cannot be treated as an unaltered account of every final legal result.