Dalcourt was walking home from work along a bike path in Paul Pratt Park when she was savagely attacked.
She died in hospital a short while later.
Mourners brought flowers, candles and other tokens to lay near the bike path. Some participated in a five-kilometre run or walk in Dalcourt's name.
Monique Dalcourt, Jenique's mother, attended the vigil.
"It's really unfair. I don't know what else to say. There are no words," she said or her daughter's violent death.
She smiled as she described her daughter to reporters. She was always a social girl and was always the first to say hello, Monique said. She thanked those at the vigil for attending.
One woman choked back tears while explaining to Radio-Canada's Jacques Bissonnet why it was important for her to be there.
"My son was the one who treated her at the hospital," she said.
A young man holding white flowers was visibly moved.
"It's the least I could do for this family. It could have been me, it could have been anybody. I often use this bike path. It affected me very deeply. My condolences to the family," he said.
Claude Lefrançois attended the vigil on Tuesday night and spoke to CBC Daybreak Wednesday.
She said it was important for Longueuil residents to take back the path and not allow it to become associated with violence.
"I went [to the vigil] because this pathway is the best, most beautiful of Longueuil and it must be kept for [the] people," Lefrançois said.
Police look for evidence
Lefrançois said she was confident police would find the person who killed Dalcourt.
"I think policemen must take their time and not make mistakes," she said.
Const. Tommy Lacroix said police have one suspect and are looking for evidence.
He would not confirm whether the man who was arrested and released earlier this week is the same man still being considered a suspect.
"We had enough proof to arrest him. It seems we didn't have enough proof to charge him," Lacroix said.
He told Daybreak host Mike Finnerty that Longueuil police wants to assure residents that investigators are doing everything they can to solve Dalcourt's death.