First came the gunfire, a series of pop-pop-pops punctuated by two loud bangs. It lasted perhaps 15 seconds, echoing across the darkened farmland where two other gunmen stood listening, both clutching shotguns.
After that there a came a shouted command, an order for everybody to get on the floor.
Then the pair stepped inside the big barn from which the shots had emanated, to encounter a scene of horror that might have been lifted from a bad movie.
Shot or frozen in motion were eight outlaw bikers from the Toronto area. Standing over them were two other men, each brandishing a rifle.
Shot in the chest and the neck, one of the victims - Luis (Chopper) Raposo, 41 - appeared to be trying to talk.
"There was blood on him and his lips were moving," a rapt courtroom heard Thursday.
"But there wasn't any sound."
The testimony at the mass-murder trial of six members and associates of the Bandidos motorcycle gang came from a defector, a biker-turned-informant who was one of the two men outside the barn that night, April 5, 2006, and who is now the prosecution's star witness.
The barn lay on the property of long-time biker Wayne (Wiener) Kellestine, 60, who according to Thursday's testimony from the informant, known by the initials M.H., was one of the two killers inside the barn that night.
The other rifle-toting man in the barn, perched in the loft and wearing a bullet-proof vest, was Michael (Taz) Sandham, 39, the leader of the Winnipeg Bandidos faction, and a onetime police officer with experience in the Canadian military.
The Crown theory in the slaughter is that Mr. Kellestine, Mr. Sandham and the other four defendants had been instructed by the U.S. Bandido leadership to strip the Toronto Bandidos of their membership - to "pull their patches," in biker parlance.
The bodies of the eight victims were found the day after the massacre, dumped in a farmer's field in tiny Shedden a short drive from the Kellestine farm.
In essence, the victims walked into an ambush when they ventured down to the Kellestine farm that evening, the prosecution contends.
And until he became a police agent, M.H. - the sergeant-at-arms for the Winnipeg group - was part of the group alleged to have committed the killings.
Now he is in the witness protection program, his new identity and location closely guarded by provincial police.
Along with fellow Winnipeg Bandido Dwight (Big D) Mushey, 41, one of the accused six, M.H. donned gloves and waited at the back of the Kellestine barn, their shotguns at the ready.
As the visitors rolled in from Toronto in four vehicles, arriving at the isolated Kellestine farm west of London one by one, their headlights piercing the darkness as they pulled in the driveway on the Aberdeen Line, M.H. and Mr. Mushey watched, M.H. testified Thursday.
If his evidence is believed by the jury, the alleged assassins knew what was likely to happen. More than once, he said, their host Mr. Kellestine had told them during their two-week stay at his run-down farm that if one of the Toronto Bandidos was killed, they would all have to be killed.
On the afternoon of the massacre, Mr. Kellestine had sent away his spouse and young daughter to stay with friends, together with the girlfriend of co-accused Frank (Frankie) Mather, 35, who had been staying at the Kellestine farm.
Thursday, M.H. described what he witnessed when he and Mr. Mushey stepped inside the barn after the gunfire.
The first person he saw was Mr. Kellestine, pointing a .22 rifle chest-high, tied to his wrist with a strap.
(A defence lawyer asked that the rifle, a court exhibit, be removed from its plastic sheath for a better view. The request was declined after the court was told that the weapon might have five different DNA sources on it.) Then M.H. began identifying the dead and wounded, using their biker nicknames.
The first he saw was George (Pony) Jessome, 52, lying on the floor face down, neither speaking nor moving.
Close by was George (Crash) Kriarkis, 28. He too was face down and motionless.
So too was Paul (Paulie) Salerno, 43.
Then M.H. looked up and saw Mr. Sandham, who had climbed up to the barn loft with an aluminum ladder.
"He was holding the .303 rifle, pointing it down toward the floor."
Sitting on the floor mortally wounded, with one arm on an old couch, was Mr. Raposo.
Then M.H. spied Frank (Bammer) Salerno, 43. He too was face-down and motionless.
Also prone, but lying face up, was Jamie (Goldberg) Flanz, 37.
Then M.H. saw John (Boxer) Muscedere, 48, president of the Toronto chapter, whose reputation as a tough guy had made Mr. Kellestine wary, M.H. testified.
Mr. Muscdere was also on the floor, not moving.
Finally, although not immediately, M.H. spotted Michael (Little Mikey) Trotta, 31, the only one of the eight Toronto Bandidos still on his feet.
Whether Mr. Trotta had been shot and wounded at that point was unclear.
The witness will continue his examination-in-chief Friday.