Witnesses recount last moments of Brandon Volpi's life after prom night stabbing

Brandon Volpiclutched his bleeding throat and shouted, "Who did this? Who did this?" after being stabbed during a prom night brawl, a security guard who came to the teenager's aid testified at the second-degree murder trial of Volpi'saccused killer.

• Defence in prom night killing trial takes aim at Crown's video expert
• Brandon Volpi killed intervening in prom night fight over cellphone, Crown says

The Crown alleges Devontay Hackett, now 21, fatally stabbed Volpi during the June 2014 fight outside Les Suites Hotel in downtown Ottawa before running away.

Brandon Armstrong, who was on duty as a security guard at the hotel on the night of the killing, told the court he was alerted to the fight just outside the building's front doors, where he encountered a confusing scene with people screaming and shouting. Armstrong said Hackett was goneby the time he arrived.

He said he saw Volpi holding his neck, and when the 18-year-old took his hand away Armstrong saw skin peeled back and could see Volpi's muscles and trachea.

Volpi appeared irate and confused, and demanded to know who had caused his injuries, said Armstrong.

'I did my best,' guard testifies

Armstrong applied gauze toVolpi's neck to stop the bleeding, but said the teenager was growing paler and paler.

"I did my best to help him," he testified.

Armstrong said he tried to keep Volpi upright with his neck elevated, but Volpi slumped over with "his eyes rolled back." Armstrong and another security guard with emergency medical training began performing CPR on Volpi while someone else called 911.

When he removed Volpi'sblood-soaked shirt, Armstrong noticed "a one-inch-long cut" in Volpi's chest.

Chest wound fatal blow, Crown says

During his opening statementon Tuesday, assistant Crown attorney Michael Boyce said a 10-centimetre-deep penetrating stab wound through Volpe's rib cage and into his heart was the injury that killed him.

The jury of eight men and four women also heard from Ottawa Police Service Const. Cheryl Cross, who arrived as paramedics were working to revive Volpi.

Cross said while she was in the ambulance with Volpi, he told her his first nameand his date of birth and that he "had to fight off a bunch of guys."

She stayed with him and the medical team in the emergency room until Volpi was pronounced dead at 5:06 a.m.

Video expert cross-examined

Hackett's lawyer, Joseph Addelman, continued his cross-examination of civilian police forensic imaging expert Mike Ross earlier Thursday.

Addelman and the Crown had entered an agreed statement of facts in which the defence acknowledged cellphone videos shown in court earlier showed Hackett fighting with Volpi..

Ross hadtestified the videos showed Hackett with a "light-coloured object" in his hand before he andVolpibegan fighting. He also said as Hackett fled the scene, the object now appearing dark in the video because of the lighting outside the hotel could also be seen.

But under cross-examination on Thursday, Ross agreed with Addelman that during the time Volpi and Hackett were actually fighting and grappling with each other,it didn't appear there was anything in Hackett's hand.

But when re-examined by the Crown, Ross again reiterated that the object could be seen as Hackettfled the fight.

Thursday's last witness was forensic identification officer Sgt. Jim Killeen, who worked the scene after the stabbing.

Killeen said there were blood stains on the pavement near where the fight took place, as well as a few drops in an alley betweenLes Suites Hotel and the neighbouring NovotelOttawa hotel. There were also blood stains found outside and inside a vehicle in the alleyway, he testified.

A white, blood-stained T-shirt was also recovered in the Arts Court parking lot on Daly Avenue, next tothe hotels, he said.

Court had earlier seen security footage of a young man in a white shirt walking into the alley and into the vehicle before getting out again.

Hackett, the accused, had also been identified in cellphone videos of the fight as wearing a white shirt.