The sister of Jeremy Cook told a London, Ont. jury about the last time she saw her little brother alive, moments before he was killed in a dispute over a lost cell phone. 

Kayla Cook told the jury she was with her brother in the pre-dawn hours of June 14, 2015 as he used an online app to track down a cell phone he had lost earlier that night. 

The Crown alleges Jeremy Cook was killed when he was shot to death following a confrontation with two men in a parking lot in London's Highbury Ave and Cheapside Street area.

One of the suspects, 23-year-old Mulhab Sultan, died after he drowned in the Rideau River while trying to evade police in Ottawa. 

The other suspect, 26-year-old Mohamed Sail, is accused of second-degree murder in connection with Cook's death and has pleaded not guilty. 

Brother clung to a speeding car

On Wednesday, Kayla Cook told a London jury how she watched her brother clinging to a car as it sped away after the siblings had unsuccessfully tried to get two men to hand over Jeremy's iPhone.

The Crown alleges Sail shot Jeremy Cook twice and left him bleeding to death in the parking lot of a commercial plaza half a kilometre away.

London Courthouse

The trial is expected to last four to five weeks. (Chris Ensing/CBC)

Kayla Cook testified she and her brother were celebrating on the night of June 13, 2015 and had called for a number of taxis to take them to Jack's, a Richmond Street bar, where they would continue their celebrations.

"It was a friend's birthday," she said. 

The two became separated and when they met each other at the bar, Cook testified her brother told her he believed he had lost his cell phone in the back seat of the cab, but she reassured him he had left it at home.

Tracked phone using app

It wasn't until they had returned home and Kayla had gone to bed that her brother realized he'd lost the phone.

Jeremy had tracked it to a parking lot close to their house in the Huron and Highbury area using an online app.

Cook testified that he woke her up at about 5 a.m. because he was becoming increasingly worried about his phone, which she said contained information relating to his business.

The app showed the phone wasn't far away and that it only had 10 per cent battery left.

It was their last chance to get the phone, she told the jury. "Otherwise, it would be lost forever." 

Kayla Cook testfied they got in his car and she drove because she had had the least to drink. Jeremy sat in the passenger seat, following the tracking app's map on her phone. 

At 5:15 a.m. the app led them to a McDonalds at Highbury Avenue and Cheapside Street, where they found three men in a car. 

Cook testified that she asked the men nicely whether they had found a lost cell phone. That's when the man in the back seat high fived the other two before leaving. 

'I was asking nicely'

"I was asking nicely, straight forward," Kayla Cook told the court, noting the two men suggested she try calling the phone. 

 "The guy reached into the back and when he pulled it back, it looked like he had it," she said. "It was in his hand when he picked it up. He said 'Hello' right in front of me."

She testified she said "hello" back just to make them understand it was the phone she was looking for and then she asked for it again.

Muhamed Ibrahim Sail

Muhamed Sail, of Calgary, has pleaded not guilty to second-degree murder in Jeremy Cook's 2015 death.

This time, she said, they claimed they didn't believe the phone was Jeremy's. They asked for the security code to prove it, so Cook said she leaned into the window to enter it. She told the court Sail wouldn't let go. 

"It seemed as if he didn't want me to touch the phone," she said. He pulled it away each time she tried to enter the code.

Car sped off 

Cook said that as soon as she had entered the code, the driver stepped on the gas. 

"I was still half in the car," she told the court, saying she was knocked down as the car lurched forward. 

She described seeing her brother Jeremy grab onto the window with both hands, lifting his feet off the ground in order to stay with the moving vehicle. 

She said she dialed 911 and was running after the car and her brother. She told the jury the vehicle made a right turn before disappearing from view. 

It was the last time she would ever see her brother alive. 

The trial continues Thursday and is set to last four to five weeks.