the investigation. so how did they do it? >> to be honest, the investigation started very small. it was an investigation about money laundering. but following the money, the investigation grew, and wow, for all of us, police officers, prosecutors, judges, not only me but the other judge involved in the case, for all of us, it was a prize. >> it began in the capital city of brasilia in the most mundane of places, a gas station, that had once housed a car wash. in what came to be known as operation car wash, the police tapped the phones of a money transfer business housed there, and in 2012, they heard the voice of alberto yusef, an infamous money laundering, the "new york times" reported. anyone linked to him immediately came under suspicion. in 2014, police arrested yusef and roberto costa, a former executive of brazil's state-run