The parents of a university student who killed himself by jumping in front of an LRT train last week are pleading for the return of his knapsack.

Jonathan Langille, 19, died last Wednesday afternoon at the Coliseum LRT station.

His mother Jan Thorpe and stepfather Shawn Egan say someone ran off with the knapsack their son left on the platform after watching him jump.

Jonathan Langille

Jonathan Langille, 19, was attending King's University College in Edmonton. (Courtesy of Jan Thorpe and Shawn Egan )

“Watched and looked right at it and picked up the backpack and left,” Egan said, shaking his head  “Guess you won’t need that anymore.”

Security video from inside the LRT station shows Jonathan placing something inside his pack before he jumped. His parents believe it may be a note.

They believe his journal may also be inside.

“[It] had everything that he recorded from every day of how he felt and what was going on,” Thorpe said.

“We just need some answers. We need some closure and I hope get that.”

His sister Katie agrees.

“I’d like to see if he had anything like a note or anything like that because I just can’t comprehend that he’d leave me.”

Thorpe says that her son had broken up with his girlfriend just before Christmas. He was depressed but seemed to be coming around.

“He seemed to be doing better,” Thorpe said.

“And he was coming out again and he was playing games and we were watching movies and we were doing all kinds of things together. It was like having the old Jonathan back.”

Edmonton Police say the suspect is an aboriginal female in her late teens, with long dark hair and average height.

She was wearing white jeans, grey boots, a grey sweater and a blue Adidas-style jacket with white stripes on the arm.

With files from the CBC's James Hees