Thai soldiers are believed to have shot an Italian photographer who was killed during mass opposition street protests in Bangkok in 2010, an official inquest found on Wednesday. The probe by a criminal court in the Thai capital, however, was unable to identify the individual who fired the bullet that struck Fabio Polenghi, a freelance photographer who was covering the two-month-long demonstrations. "During the inquest, experts testified that the victim died of a wound from a high-velocity bullet like those used by security forces and there was no evidence of any other group in the area," according to a criminal court judge. "The court ruled that Fabio Polenghi died from a wound from a gunshot which came from the direction where security forces were working to regain control of the area but could not identify the shooter," she added. Polenghi was killed on May 19, 2010, the day when soldiers firing live ammunition stormed the "Red Shirt" protest movement's sprawling rally base in the centre of Bangkok. His sister Elisabetta Polenghi said the ruling was "positive but it is not the solution". "Now I'm expecting that something really happens and the ones who are responsible have to get a kind of penalty," she told reporters.Her lawyer said that he would file a criminal complaint with the Justice Ministry's Department of Special Investigation (DSI) against Abhisit Vejjajiva, who was prime minister at the time. "Now we have the official ruling from the court, I, as a legal advisor and lawyer of the Polenghi family, will go to the DSI to file a complaint against former prime minister Abhisit," said the lawyer, Karom Pornpolklang. Police told the inquest they believed security forces shot Polenghi during the demo, in which tens of thousands of Red Shirts brought central Bangkok to a standstill with demands for snap elections. Street battles between soldiers with rifles and mostly unarmed protesters claimed more than 90 lives and left nearly 1,900 people injured, mainly civilians. Abhisit and his former deputy Suthep Thaugsuban face murder charges in connection with the deadly crackdown, officials announced in December. No military officials have been prosecuted. Current prime minister Yingluck Shinawatra's government has said there is clear evidence that troops were responsible for the death of another journalist during the unrest, Japanese cameraman Hiroyuki Muramoto of the Thomson Reuters news agency.