It's a 35-year-old mystery involving a baby, a breadbox and a tormented mother, and it has led police in Montreal to plumb the depths of a municipal parking lot in search of clues.
Montreal detectives have enlisted the help of the city's École Polytechnique engineering school in an effort to solve the disappearance three and a half decades ago of a girl named Yohanna. Using high-tech earth probes, police turned an expansive city lot into a potential crime scene, seeking traces of an 18-month-old toddler who vanished in 1978.
"A crime scene speaks. And sometimes, the earth can talk and give us answers," Montreal Police Commander Dominique Verret said.
In this case, its secrets could help close a chapter for a woman named Liliane Cyr.
On an August afternoon when she was 19, Ms. Cyr left Yohanna in the care of her boyfriend while she went to a job out of town. She never saw the little girl again.
The boyfriend, a U.S. citizen, initially told Ms. Cyr the child had drowned in the bath, and he had notified police and held a burial. Later, under questioning by police, he denied he had been babysitting Yohanna. He was acquitted on an abduction charge, and the trail went cold.
Police reopened the file in 2011, after a detective named Marie-Julie Durand championed it as a cold case. Ms. Cyr offered her a tantalizing lead.
At the time of the child's disappearance, Ms. Cyr lived in a boxy, red-brick apartment building abutting a field covered in grass and shrubbery.
The superintendent of the apartment block remembered seeing a man leave the building the night of the disappearance at around midnight. He was carrying what appeared to be a breadbox.
Police recently scoured aerial photos of the neighbourhood from the 1970s. They zeroed in on the field. Today, it's a parking lot.
"We think the body might have been buried in that area," Commander Verret, head of investigations for the Montreal police's western region, said in an interview.
Lacking their own equipment, police turned to University of Montreal's École Polytechnique and geophysics professor Michel Chouteau. Police had sought help from Prof. Chouteau before, in finding a drug cache buried by the Hells Angels. Prof. Chouteau had declined, hesitant to embroil academe in the violent underworld of criminal bikers.
This time, for a mother seeking her lost child, and at the urging of Sgt.-Det. Durand, Prof. Chouteau agreed.
"She [Ms. Cyr] has been waiting for 35 years to find out what happened to her daughter."
A team of geological-engineering students spent a day in the parking lot in Montreal's St. Laurent borough one day this month, methodically scanning the site along a tight grid. If the baby was buried inside a metal breadbox, the school's highly sensitive equipment, including ground-penetrating radar and a magnetic-field tracker, would find evidence of it.
Results are expected next month.
"This is the first time in Quebec we've used this kind of equipment for a search like this," Commander Verret said. "We're trying to close all possible leads."
Police also went to the United States to interrogate the ex-boyfriend, who is considered a witness.
For Ms. Cyr, who is supported by the Missing Children's Network, the hunt at the parking lot could offer a degree of comfort after decades in the dark. All these years, she has wondered: Was her baby alive somewhere? And if not, where is the body?
In 1978, a month after Yohanna's disappearance, the tabloid Journal de Montréal plastered the girl's face on its cover with the screaming headline: "This baby may have been sold in the U.S." Last year, the RCMP drew up an updated sketch of what Yohanna would look like today.
"What I want is my daughter, either dead or alive," Ms. Cyr, who now has two grown daughters and five grandchildren, said recently as she stood beneath a grey spring sky at the parking lot. She contemplated the possibility that the cracked concrete before her held the answer to a long, painful search.
"If she's dead, I'll give her a proper burial," Ms. Cyr said. "At least bring me a body, so I can close the book."