Mauricio Funes spoke to his son on the night before his death
The president-elect of El Salvador has made an emotional statement at a trial for his son's murder in Paris.
"I am a man who is not seeking vengeance... only the truth," said Mauricio Funes. He wept in court.
Alejandro Funes, 27, a photography student in France, died in October 2007 from stab wounds on a pedestrian bridge near the Louvre Museum.
Mohamed Amor, the main suspect, has asked the family for forgiveness. The motive of the attack is unclear.
Mr Amor has already told the court he cannot remember exactly what happened.
"I never wanted to kill him," he said. If found guilty he could spend up to 30 years in prison.
Another suspect is also on trial for allegedly participating in the attack.
Mr Funes spoke to his son by telephone the night before his death.
"The least we can hope for is to know the facts and establish who is responsible," he said.
"All this will not bring back my son, but I want to honour his memory," he added.
The weapon used to kill Alejandro is believed to have been an awl - a pointed tool for making holes in wood or leather.
President-elect Funes's brother was shot dead at the beginning of El Salvador's civil war in 1980 and safety had been a factor in Alejandro leaving the country, plagued by gang violence, to study in France.
"We thought he would be safer here.. I would never have imagined that he would be beaten to death here," said Mr Funes, unable to stop himself from crying as he spoke.
The left-wing leader, who takes office in June following his electoral victory in March, paid tribute to his son.
"We shared the same ideals, the same life projects and the desire to transform El Salvador, to convert it into a just society that would put an end to violence," Mr Funes said.