Police in London, Ont., say the slaying of an 18-year-old man over the weekend highlights the risks involved with tracking missing cellphones using mobile apps.

Jeremy Cook was shot multiple times behind a strip mall in the northeast part of London early Sunday.

Jeremy Ryan Cook is seen in this family handout photo made available by the London Police Service.

After losing his cellphone in a taxi, he used a tracking application to follow it to the strip mall at Highbury Avenue and Huron Street, police said.

Cook and a relative approached a silver 2004 Mazda with three suspects inside at approximately 5:15 a.m. on Sunday, police said. The car began to drive away and Cook grabbed hold of the door, at which point he was shot multiple times.

Police say the three suspects fled, eventually crashing into a pole and a fence before abandoning their vehicle a few blocks to the west, near the city’s Ed Blake Park.

Cook's cellphone was located near where the suspects' vehicle was abandoned.

Investigators are now looking for three black male suspects between the ages of 18 and 21.

One man was last seen wearing a white shirt with a black design. A second suspect is described as having very short hair and was wearing a black jacket or shirt, along with a fitted a hat. And the third suspect is described as having a slim build and was wearing a blue shirt and a black hat.

Cook had no previous involvement with the suspects and was not known to London police.

Jeremy Cook, left, and friend Kasia Szymanski are seen in this photo made available by Kasia.

Const. Ken Steeves urged anyone tracking a missing cellphone to tread carefully when entering potentially dangerous situations.

"The app is not what makes the scenario dangerous -- it is the human beings or the people you interact with," Steeves told CTV News Channel.

"So, our advice is if there is any indication of violence, or of potential violence, just give us a call … and we'll attend," he added.

Technology analyst Carmi Levy told CTV London that youths tend to overvalue their cellphones, and parents need to be aware of potential risks.

"It is an incredible tragedy that all parents who have kids with cellphones need to understand," said Levy.

"Unfortunately kids seem to think their phones are incredibly valuable – they're not. It's a couple of hundred bucks to replace it – certainly not worth your life," he added.

Cook, who is originally from Brampton Ont., was living in London for a carpentry internship and planned to attend college in the fall. He was also running his own furniture business on the side.

A small memorial near the scene where 18-year-old Jeremy Cook was fatally shot, in London, Ont., Tuesday, June 16, 2015.

Kasia Szymanski called her friend’s death "senseless and cruel."

"And over what, a phone? He was an amazing guy, who was at the wrong place at the wrong time. He had so much going for him," she added.

At his Brampton high school, where Cook had recently graduated, teachers described a talented student with a bright future.

"He was a good kid, who did a lot of stuff with the woodworking (and) he was in college doing cabinet making," one teacher told CTV Toronto.

Mourners placed flowers and stuffed animals on the pavement where Cook's body was found.

Local resident Liat Morgan did not know Cook, but left a statuette of an angel at the memorial.

"The fact that he died so tragically over a cellphone. It's so trivial and it's not fair," Morgan said.

"I can only imagine what the mother must be going through," she added.

With a report from CTV London, CTV Toronto and files from The Canadian Press