Russell, 35, died after trying to stop a snowplow that was being driven erratically on Toronto streets on the morning of Jan. 12, 2011.
After the 11-year police veteran was struck by the snowplow, a tow-truck driver rushed to his aid.
Among the first police officers to reach his side was Sgt. Sarah Andrews, who told jurors Wednesday that Russell was face down when she got to the scene.
"I dropped to the ground and I tried to roll the body over," she said. "I ended up rolling him on top of me and it was at that time I realized it was a police officer."
Andrews said there was blood everywhere and that Russell wasn’t conscious.
“I took his left hand and I held it and I could feel his wedding ring and I just kept talking to him telling him that he had to fight and to hold on, help was coming," Andrews said in court.
"I kept asking for help on the radio and another officer finally came ... He helped me loosen up his vest and I put my hand under his vest to see if I could feel his heart beating. He was warm, but I couldn't feel his heart beating."
Jurors also heard testimony from Herculano Pereira, the tow-truck driver who ran to help Russell after he was hit.
He tried using the officer's radio to call 911. He couldn't tell if Russell was breathing.
"The officer was face-down on the ground — there was blood running down from his head," Pereira told the court Wednesday.
Under cross-examination, Pereira said that if Russell had been struck in a way so that his body had been knocked away from the centre of the plow, he might have survived.
Russell was pronounced dead in hospital later that same morning. He left behind a wife and a young son.
Signs of trouble emerged quickly
Inside the courtroom Wednesday, jurors heard from more witnesses who saw the lead-up to and the collision that claimed the officer's life.
Maurice Lopes was driving behind the snowplow on Avenue Road. At first, he didn’t realize what was going on.
"It's only when I hear three gunshots that it first dawns on me that there's something amiss," Lopes said in court Wednesday.
Vance Cooper, a lawyer, was driving behind Lopes that morning.
Like Lopes, Cooper wasn’t initially aware there was a problem. He believed that Russell was trying to get traffic to stop and directing the vehicle.
But that changed quickly when the vehicle started advancing on Russell.
"I'm just holding my breath and hoping the officer can get out of the way in time," he told jurors.
Cooper said the snowplow made no attempt to slow down or change direction as it approached the doomed officer.
He couldn't see the gun that Russell was holding, but he remembers hearing either two or three shots.
Under cross-examination, Cooper said the entire incident only lasted seconds.
Electrician Hamid Azarbani was on his way to work and had a clearer view. He saw the plow hit Russell.
"I saw half of his body, almost, it was struggling on the ground and looks like [the plow] was dragging him about 15 feet," he said Wednesday.
"He was shaking and all of a sudden stopped."
The Crown has previously told jurors that the snowplow hit the officer in the leg, knocking him over. Russell was also hit in the head and the force of the collision fractured his skull, the Crown has said.
The man accused in the officer's death is Richard Kachkar, a 46-year-old man charged with first-degree murder and dangerous driving. He has pleaded not guilty to both counts.
Ontario Superior Court Justice Ian MacDonnell has told jurors that there is no question that Kachkar drove the snowplow that day.
The trial, now in its third day, is about the state of mind of the accused when he was behind the wheel.
Jurors have already seen the video captured by Russell's dashboard camera and they have also heard the final radio call he made to a police dispatcher.
During his final radio call, Russell was recorded saying that the snowplow was driving at him. Then there was silence.