The Quebec man charged after a pickup truck plowed into pedestrians last month is now facing three counts of first-degree murder.
On March 13, a truck hit several groups of pedestrians on a main street in Amqui, about 350 kilometres northeast of Quebec City, in what police have described as an intentional act.
Gagnon, 38, was facing two counts of dangerous driving causing death, but the prosecutor had indicated more charges were expected, and a third victim has since died.
Three men were killed in the crash: Gérald Charest, 65, Jean Lafrenière, 73, and Simon-Guillaume Bourget, 41.
Charest and Lafrenière were killed the day of the crash while Bourget died several days later in a Quebec City hospital.
The truck hit 11 people ranging in age from less than a year old to 77.
Gagnon, who has been in custody since the incident, is due back in court on Wednesday.
