Lison Blais, 17, was found dead behind her family home at 4685 Christophe-Colomb Street in Montreal on the morning of June 4, 1978, after a night out with friends. She left Bar Chez Philippe at about 3:25 a.m.; how she returned to the neighbourhood has never been established publicly. Her body was discovered around 9:00–9:20 a.m., partially undressed, with extensive head and facial trauma including numerous open fractures consistent investigators believed with a brick, strangulation marks, and evidence of sexual assault with an object. Her clothing and a black purse were missing, as were a pair of pants that had hung on the family clothesline the previous day. Neighbors and a sister who had a rear-facing bedroom reported hearing no disturbance.

The coroner’s inquest was suspended in November 1978, and no significant breakthrough was made public afterward. A black purse recovered in 2006 resembled the missing purse but forensic testing produced no usable DNA. No publicly documented suspect has been charged; the family later reported being told the file was closed around 2009–2010 and that evidence had been destroyed. The killer’s identity remains unknown. If anyone knew Lison, saw her leaving the bars that night, or saw a black purse or missing clothing in the area afterward, does that information still exist?