Secretary-General Ban Ki-moon, who made the appointment, thanked Mr. Castresana – who resigned earlier this month – for his “excellent work” heading CICIG since its inception two and a half years ago.

“The achievements of CICIG during that period have been praised by Guatemalan authorities, civil society and the international community alike,” Mr. Ban said.

Since becoming Costa Rican Attorney-General in 2003, Mr. Dall’Anese has waged campaigns against narco-trafficking and organized crime, led major investigations against corruption and helped introduce prominent legislation against organized crime.

Mr. Dall’Anese has also served as an alternate magistrate in the Supreme Court, taught criminal law at university and co-authored numerous books and articles on criminal, judicial and procedural law. In 2005 he received a prize from the National Values Commission for his work against organized crime.

The UN and the Guatemalan Government set up CICIG as an independent body to support the public prosecutors’ office, the national civilian police and other institutions to investigate a limited number of sensitive and difficult cases regarding illegal security groups and clandestine security organizations and also dismantle them.

Based in Guatemala City, the capital, the Commission seeks to bolster the rule of law and is permitted by its mandate to conduct independent investigations and help authorities bring representative cases to trial in national courts.