03/07/2012 11:18 EST | Updated 05/07/2012 05:12 EDT

Officer's final minutes shown in Ottawa murder trial

Const. Eric Czapnik ran into the Ottawa Hospital looking for emergency treatment as he fought to save his own life, surveillance video showed in the trial of a former Mountie who is accused of killing Czapnik.

The video recorded by cameras inside the hospital also showed paramedics rushing to Czapnik's aid. One camera caught Czapnik running inside looking for help. Blood can be seen on his jacket as he clutches his neck, after he had been stabbed outside in the hospital parking lot.

Kevin Gregson, 45, is charged with first-degree murder in the death of the 51-year-old Czapnik, who was stabbed outside the Civic Campus of the Ottawa Hospital in the early morning of Dec. 29, 2009.

Gregson is also charged with robbery in relation to a carjacking the night before the stabbing. He has pleaded not guilty to both charges.

Accused's brain condition not linked to aggression

Dr. John Sinclair, a neurosurgeon at the Ottawa Hospital, and Dr. Michael Kingstone, an expert in diagnostic neuro-radiology, each testified Wednesday about Gregson's condition the night of Czapnik's death.

Kingstone said Gregson did have a brain condition called hydrocephalus in 2006, but a shunt inserted into his brain had fixed that condition. Gregson was still irritated by the condition, though, the court heard.

Sinclair told the court hydrocephalus does not cause increased aggression. It causes confusion headaches, nausea, drowsiness and can cause death. He also said tests showed no there were no effects in 2009.

Sgt. Tim Hodgins, who interviewed Gregson for three hours, also returned to the witness stand Wednesday. The defence decided not to cross-examine him.

The Crown rested after the two doctors took the stand. The defence will begin its case Thursday morning.

Long interrogation tape shown to jury

The interrogation tape was shown in court Tuesday and parts were repeated Wednesday, along with some surveillance video inside the hospital.

The interrogation tape did not show Gregson confessing to the slaying of Czapnik, but it did show him confessing to the carjacking.

He said he was trying to kill himself with a knife that night in December 2009, but failed. Gregson then said on the tape he decided he needed a gun and went to the hospital where he knew he would find police officers.

Gregson also eventually said into the camera, "I'm really sorry about your dad," speaking to the officer's three children. But he did not say what he was sorry for.

The court also heard Monday the former Mountie had an emotional confrontation with his ex-wife over an alleged sexual assault of a 10-year-old girl just a day before Czapnik's death.

Gregson was also said to be seeking work overseas in 2009 and wanted a position where he could use firearms.

The defence is expected to start its case today or Thursday once the Crown finishes presenting all of its evidence.