A 36-year-old woman faces preliminary murder charges for police found the bodies of her three newborn babies stuffed inside plastic bags and hidden at her home in the French Alps.
Police said they were tipped off by Labrosse's former partner, who was questioned and released without charge on Friday. Her current partner, a 20-year-old man, was also questioned and released.
"She acknowledged that the three children were those of her former partner," state prosecutor Henry-Michel Perret told reporters. He said preliminary charges were to be filed against Labrosse later Friday related to the murder of minors.
Perret said questions remained about her statement, because the former lover who found the bodies - a 40-year-old plumber - was in prison at the time of her first pregnancy, for a sexual assault conviction.
"That could have played a role in her decision not to keep the child," said Perret. "Why did she keep them (the bodies)? That's the mystery of this case."
The plumber, who was not identified, had alerted police to the discovery of the bodies - two tucked in a trunk, and the third found in a box holding an artificial Christmas tree, Perret said.
An autopsy of the bodies - one boy, one girl, and one still unidentified - was expected Saturday, and analyses of how they died would determine what kind of sentence Labrosse could face if convicted, Perret said.
Labrosse, who worked a temporary job at Albertville City Hall, had initially conserved the bodies in a freezer, he said.
Under French law, preliminary charges mean an investigating judge has determined there is strong evidence to suggest involvement in a crime.
The filing gives the magistrate time to pursue an investigation that can result in a trial or the dropping of charges.