An emergency doctor treated an alleged murderer shortly after trying to save the police officer Kevin Gregson is charged with stabbing to death.

Dr. Guy Hebert was Chief of Emergency Medicine at the Ottawa Hospital's Civic campus on Dec. 29, 2009 when he got a frantic page on the overhead PA around 4:30 a.m.

He said as he was running to the call he could see a trail of blood leading from the doors to the room where Const. Eric Czapnik was being treated by paramedics, bleeding profusely from both sides of his neck.

"It was really quite a scene because there was blood everywhere," testified Hebert Thursday during Gregson's first-degree murder trial.

Hebert took a resident's hand and told them to cover the large wounds on his neck while other doctors started performing CPR on the officer, who was without vital signs at the time.

Czapnik was moved to a trauma room as doctors worked on his chest and neck, as Hebert said he was losing more blood then they could transfuse back in.

He said the team worked for 50 to 60 minutes on Czapnik, giving enough blood to fill his circulatory system twice over.

However, the bleeding was too severe and he was pronounced dead at 5:26 a.m. that day.

Hebert said he was then called to treat Gregson, a former RCMP officer accused of stabbing Czapnik to death as he sat in his cruiser outside the hospital.

Gregson was attached to a gurney with handcuffs and surrounded by police officers when Hebert arrived.

"He was very quiet, maybe a bit dejected," Hebert said. "Just looking at the floor."

Gregson had gauze wrapped around his neck to treat "simple lacerations on either side."

Hebert said he didn't appear to be under the influence of alcohol or drugs.

Gregson asked for TV in his cell after arrest

Police officers who were among the first on the scene were the next to testify.

Const. Gregory Thompson was watching Gregson when he noticed he had handcuff keys in his pocket.

"I came here looking for a fight," he said that Gregson told him. "You city cops are tough."

When Gregson was taken into custody, Thompson said the prisoner laughed as he asked him for a heater and a 52-inch plasma TV for his cell before apologizing seconds later.

He added the accused sat down on his bed, faced the wall and asked him about the prison on Innes Road as well as if the Ottawa Citizen had written an article about the incident yet.

Const. Carl DeJong testified that he asked Gregson if he knew why he was at the hospital.

"Because I killed a cop," he said was his reply.

The jury was also shown graphic photos from Czapnik's autopsy, with his widow and children in the courtroom.

The trial resumes Thursday, with more details expected on Gregson's past.

With a report from CTV Ottawa's Catherine Lathem, who is live-tweeting from the Ottawa courthouse.

WARNING: Some of her tweets contain graphic descriptions of evidence and testimony.