LONDON, Ont. — Police are searching for three suspects after a teen who recently moved to the city to pursue a carpentry career was gunned down in a parking lot Sunday while trying to track down his lost cellphone.

Officers arrested three men in a cab soon after the deadly shooting of Jeremy Cook, 18, but they were released after it was determined they weren’t involved.

"We had reasonable grounds at the time to arrest these individuals because at the time there was reason to believe they were responsible," Const. Ken Steeves said Monday.

Cook was originally from Brampton, Ont., but recently moved southwest to London. He had never been in trouble with the law in London and didn’t know his killers, police said.

So far the investigation shows Cook accidentally left his cellphone in a taxi earlier that morning or the previous night. He used a device to track the phone to an address, police said.

Cook and a relative went there and approached a silver Mazda sedan with three men in it at about 5:15 a.m. Sunday.

The men inside weren't giving the phone back to Cook, police said.

During the confrontation over the phone, one man jumped out of the car and walked away and the driver stepped on the gas.

Cook grabbed the driver's door and held onto the car as it peeled away out of the parking lot.

Police responded to the reports of gunshots and found Cook bleeding behind a plaza. He died at the scene.

The Mazda smashed into a fence and hydro pole and police found it abandoned.

"It's very tragic that an incident involving a lost phone resulted in the loss of a life," Steeves said.

"Most of the time with most of our homicides or any other violent crime such as robberies or home invasions, the offenders and victim are known to one another or have a connection. This is unique in that the victim and offenders are not known to one another."

Last summer, Cook and his business -- Cottage Chairs -- were featured in a publication by the Brampton Small Business Enterprise Centre.

He had just graduated from the city's Notre Dame Catholic secondary school, and was heading to Fanshawe College in London for carpentry, said a spokesman for the Dufferin-Peel Catholic school board.

"His passion was in carpentry and he did very well," said Bruce Campbell, adding Cook won the gold medal in the Dufferin-Peel Skills Canada competition.

"It's pretty shocking . . . that any of your classmates, former classmates or students was involved in a murder."

Chief John Pare called the shooting death tragic, noting many people have safely tracked lost or misplaced cellphones.

"These are really unfortunate and tragic circumstances for a young man starting out his life," he said.

A citizen called police after finding Cook's cellphone, police said.

When area residents learned Monday the shooting involved a dispute over a phone, they were shocked.

"A cellphone," exclaimed one man, covering his mouth and shaking his head. "Society is changing."

The death was London's fourth homicide of 2015, and the second shooting death.

-with files by Emanuela Campanella