Public prosecutors on Thursday asked the court to confirm the identities of the three victims and rule on where, when and under what circumstances they died. The three requests were made under Section 150 of the Criminal Procedures Code.
The three dead protesters are Thanusak Rattanadej, 29, Jirapong Chuichai, 29, and Sattha Sae Dan, 44.
The case stems from street protests that were launched following the House of Representatives' consideration of a blanket amnesty bill covering those who took part in political violence from 2004 to May 2010. A group called the People's Democratic Force to Overthrow Thaksinism began to rally at Sam Sen railway station on Jan 13 before moving to Chamai Maruchet bridge.
Meanwhile, the People's Democratic Reform Committee, led by Suthep Thaugsuban, had begun its own demonstration against the Feb 2 general election and called for then-prime minister Yingluck Shinawatra to resign.
Under a government emergency decree, 14 companies of police were deployed to clear protesters from Phan Fa bridge and Victory Monument on Feb 18. Negotiations failed leading to a clash involving guns and M67 hand grenades. Two police officers were killed and one seriously injured.
Three protesters were killed at the Chamai Maruchet bridge. Thanusak died of injuries from grenade shrapnel to the abdomen. Jirapong and Sattha were shot in the chest. Their relatives believed the three were killed by authorities.
Sam Sen police investigators concluded from the autopsy that the three died of unnatural causes, prompting prosecutors to ask the court to investigate and confirm.