PARIS (AP) — The landmark trial of three former Syrian intelligence officials began Tuesday at a Paris court for the alleged torture and killing of a French-Syrian father and son who were arrested over a decade ago, during the height of Arab Spring-inspired anti-government protests.

International warrants have been issued for the defendants, being tried in absentia.

The father Mazen Dabbagh and his son, Patrick, were arrested in the Syrian capital, Damascus, in 2013, following a crackdown on demonstrations that later turned into a brutal civil war, now in its 14th year. The probe into their disappearance started in 2015 when Obeida Dabbagh, Mazen’s brother, testified to investigators already examining war crimes in Syria.

The four-day hearings come as Syria’s President Bashar Assad has started to shed his longtime status as a pariah that stemmed from the violence unleashed on his opponents. Human rights groups involved in the case hope it will refocus attention on alleged atrocities.