A police officer choked up Tuesday as he recalled finding the body of a little girl, her blonde hair matted with blood, inside a "chaotic" Vancouver Island apartment on Christmas Day in 2017.

Const. Piotr Ulanowski testified at the start of the trial for Andrew Berry, who has pleaded not guilty to the second-degree murder of his daughters Chloe Berry, 6, and Aubrey Berry, 4.

Ulanowski told a British Columbia Supreme Court jury that he was the first officer to enter Berry's apartment, which was strewn with clothing and had blood smeared on the walls.

After he discovered the girl's body on a bed, he left the suite and called for backup, he said.

"I remember my adrenaline pumping," he said. "I wanted to go in. At the same time, I didn't want to go in. I didn't want to believe what I'd found."

The defence has not yet had an opportunity to cross-examine Ulanowski or make arguments.

The officer said he went to the apartment on the afternoon of Dec. 25, 2017, after the girls' mother, Sarah Cotton, visited the Oak Bay police detachment to say the girls had not been returned on time, as required by a court order.

The officer said he knocked on the door but no one answered. He also tried calling Berry's phone, which he could hear ringing inside the suite but it went to voice mail. Eventually, a property manager provided a key to the apartment and Ulanowski entered just before 6 p.m.

A sergeant joined him about five minutes after he made the grisly discovery inside the suite, he said. The pair re-entered together, using flashlights because the power had been shut off, he said.

Ulanowski said he headed down a hallway on his own and entered a bathroom, which was "in complete disarray" like the rest of the home.

"That's where I located a nude male in the tub," he said.

Andrew Berry was submerged in water up to his shoulders and he had lacerations on the left side of his chest, blood on his neck and his right eye was swollen shut, Ulanowski testified.

The constable testified he called out, "Andrew, Andrew, can you hear me?"

"There was very little response but there was a gasp for air," Ulanowski said.

Earlier Tuesday, Crown lawyer Clare Jennings said in her opening statement that Berry stabbed his young daughters dozens of times each before attempting to kill himself.

Jennings said when paramedics and firefighters responded to Berry in the bathtub, he told them, "kill me," and "leave me alone."

Another paramedic assessed the two young girls, who were found dead in bloody pyjamas lying on beds in separate bedrooms, she said, adding they were stiff and cold.

"They had been deceased for some time."

She said an autopsy found Chloe Berry was also struck in the head at least once, hard enough to fracture her skull.

Andrew Berry was treated in hospital and underwent surgery to repair a serious injury to his throat or neck, she said.

While in hospital, he never once mentioned his daughters or asked how they were doing, and instead he had a series of complaints about the way his parents and the girls' mother had treated him, she said.

Forensic identification officers went to his apartment and photographed a knife on the floor near the bed where Chloe Berry was found, Jennings said.

They also found a note on Berry's living room table addressed to his sister, in which he also sets out a number of complaints about his parents and Cotton, she added.

Jennings told the jury a neighbour will testify about hearing loud noises from Berry's apartment around 8 a.m. on Christmas Day. Neither of his daughters was seen or heard from at all that day, she said.

She said a court order in May 2017 set out the parenting schedule between the two parents, with Cotton taking custody 60 per cent of the time and Berry the remaining 40 per cent.

Also in May 2017, Berry quit his job with BC Ferries. He struggled financially and by December his power had been shut off and he was due to be evicted because he was behind on rent payments, she said.