Four suspected members of Hezbollah are on trial in absentia for the assassination of Hariri in a massive 2005 bombing in downtown Beirut. Their trial before the Special Tribunal for Lebanon is slated for January.
Former tribunal prosecutor Herman von Hebel defended the slow pace of the tribunal. Critics said the revolving door of chief prosecutors is muting its effectiveness.
"Justice is a very delicate and thorough process, but that also means not a very fast process," he said in an interview published Thursday by The Daily Star. "Speedy justice often is not really justice."
Three prosecutors have led the tribunal since it was established in 2009. Von Hebel is now a jurist at the International Criminal Court.
The tribunal last year released the names of suspects -- Salim Jamil Ayyash, Mustafa Amine Badreddine, Hussein Hassan Ainessi and Assad Hassan Sabra -- who are wanted for the bombing attack in which 22 people died.