Investigators are hoping the seven-year-old British girl who survived the shooting of three members of her family will provide the key to solving the killings.
Iraqi-born Saad al-Hilli, 50, was gunned down in his car alongside his dentist wife, named by neighbours as Iqbal, and a woman believed to be her mother.
The couple's children, four-year-old Zeena and Zainab, seven, are apparently the only witnesses to the shootings on an isolated French Alpine road and are now under police protection.
Members of the media survey the area in which the al-Hillis family were killed
Investigators are waiting for the green light from medical staff at Grenoble University Hospital to talk to Zainab as the motive behind the killings remained a mystery.
Annecy prosecutor Eric Maillaud said detectives hope the youngster, who is in a stable condition, will recover sufficiently from the trauma to speak to them and that her memory was not damaged.
"We are waiting for the ballistic team's report and, when possible, a hearing with the eldest girl," said Mr Maillaud.
A mark on the road near the killings is inspected
"Maybe she can give us information on the number of people present for example, or the colour of their skin, and other elements of description that might allow us to consider a bit more seriously a first lead.
"Medical staff have not yet given us access to the girl, we are waiting for their decision."
SEE ALSO:
- French Alps Shooting: Dead Father, Saad Al-Hilli, 'Known' To Security Services (PICTURES)
- Francois Hollande Says Police Will Do Their 'Utmost' To Find Family's Killer
- British Al-Hilli Family Named, Father Saad, Mother Iqbal Killed, Daughters Zainab And Zeena Survive
- Killed Cyclist Named As Sylvain Mollier