His secondary education, at St Joseph's College High School (Indonesian: SMA Kolese Santo Yoseph), was completed in 1994.

[1] Sarmento then studied law at the University of National Education (Indonesian: Universitas Pendidikan Nasional (UNDIKNAS)) in Denpasar, Bali, Indonesia; he completed his degree in 2002.

[1] In April 2004, Sarmento, acting as a representative of the Catholic Institute for International Relations, a UK-based non-governmental organization (NGO), made a statement during a General Debate on Civil and Political Rights at the United Nations Commission on Human Rights (UNCHR), about what he said were overall weaknesses in the independence of the judiciary in East Timor.

"[2]From 2004 to 2007, Sarmento was the Executive Director of the Judicial System Monitoring Program (Portuguese: Programa de Monitoramento do Sistema Judicial, Tetum: Programa Monitorizasaun Sistema Judisiál) (JSMP),[1] an NGO that monitors the justice system and engages in advocacy relating to the rule of law in East Timor.

The strategic goal of the process, as reported in the media, was the establishment of a strong judicial system, to ensure that all rights are respected, and that everyone has access to justice quickly and easily.

The assignment, for a price to be agreed later, was made in connection with a long term contract between the parties, under which the Stadium and other football fields in East Timor would be brought up to international standards, at FIFA's expense.

In particular, serious difficulties had arisen as to the public recognition in East Timor of the legal personality of ecclesiastical institutions, and negotiations over that issue had been initiated in early 2020.