Hamed Shafia admitted to hitting the car containing his three sisters and father’s first wife and watching it sink into the water in Kingston, according to testimony heard in court Friday.
Shafia, 21, previously told police in a videotaped interrogation that he had no idea what had happened to his sisters Zainab, 19, Sahar, 17, and Geeti,13, and Rona Amir Mohammad, 50, who were found dead inside the car submerged in the Rideau Canal in 2009.
They have pleaded not guilty.
Moosa Hadi, who was hired as a translator by the Shafia family after their arrest, testified in a Kingston courtroom that Hamed admitted his Lexus accidentally hit the black Nissan containing the four women and the car went into the water.
In a recorded conversation played for the jury, Hamed told Hadi he dangled a rope over the ledge of the canal to check for signs of life.
After getting no response, Hamed drove home and didn't tell anyone because he thought he would get in trouble for letting his sister drive without a licence.
Hadi made the audio recording of Hamed's story so he could present it to police, believing it would convince them of the error of their ways and they would drop all the charges. Instead, he was called to testify as a Crown witness.
Believes accused are innocent
Hadi, an engineering student, said that after speaking with all three accused, he believes they are innocent.
He told reporters outside the court he initially offered his services to the family because he learned they were having difficulty communicating in their native Dari.
He later got permission to review the prosecution's evidence and said he saw nothing that implicated Yahya or the elder Shafia and that Hamed's involvement was merely accidental.
He met with the family members almost three months after the deaths and shared some of that evidence with them.
"By that time, I was convinced that both of them didn’t know at all anything," he said outside court, referring to Yahya and Mohammad Shafia.
The events detailed by the Hadi represents the third scenario from the accused trio about what happened that night.
Immediately after the incident, Shafia and Yahya spoke with Montreal media and said one of the girls took the car keys to get clothes out of the vehicle and that was the last time anyone heard from any of the victims.
The trial continues Monday.
This story has been updated from a previous version.Nov 18, 2011 11:23 PM ET