A first-degree murder trial in Cranbrook, B.C., came to an abrupt end this week when the accused pleaded guilty to a lesser charge.

Jonathon Christopher Weisbrodt, 28, initially pleaded not guilty in the death of Bryan Allan Harvey when trial began on April 12.

On Thursday, he changed his plea to guilty of second-degree murder and the jury was discharged. Crown prosecutor Lynal Doersken said he was unsure of what caused the surprising turn.

"I can just speculate that as the evidence is coming in, he decided that enough is enough," he said.

Harvey went missing from Creston, B.C., in August 2004. A month later, his body was found in a nearby gravel pit. He had been shot to death.

After several years of investigating, Mounties arrested Weisbrodt in 2007. The jury heard that Harvey, Weisbrodt, and Harvey's mother Angie were partnered in a marijuana grow operation.

Weisbrodt's guilty plea in his fifth week of trial leaves many unanswered questions, said Doersken.

"This is one of those cases where we know he did enough to commit second-degree murder," he said.

"Some questions, as to how things happened, when they happened, are details that we may never know."

With a report from CTV British Columbia's Kimberly Davidson