Forensic police have inspected the scene of attack on the seventh floor of the building this morning and suspected grenade was used in the attack as two large glass panels were broken.
Primary inspection suspected it might be a M 79 grenade but this has to be tested again in the laboratory from traces of gunpowder on the glass panel.
Police looking through CCTV camera footages from the area but did not find any suspicious movement. They suspected that the grenade might be fired from the area opposite the Criminal Court building.
A court chief judge Mr Thongchai Senamontri said this morning the court was found for 132 years and never experienced such attack.
If the attack was meant to pressure the working of the judges, he said the Criminal Court would never yield to such threat because all cases that the court decided was based on witnesses and evidence and justice.
He asked those perpetrators to think of the safety of the people although the attack would be made at night.