A former New Zealand city councillor charged with first-degree murder in the 2010 drowning death of his wife in a Canadian lake killed out of greed, a jury has been told.

Peter Beckett's trial began in the British Columbia Supreme Court this morning [NZ time] with a lengthy opening statement from Crown prosecutor Sarah Firestone.

Ms Firestone outlined the case against Beckett, which includes wiretaps, an exhaustive financial investigation and a jailhouse snitch.

"The accused killed Laura Letts deliberately for financial gain," she said, noting he hoped to benefit from her family inheritance and insurance payouts.


"He would also collect her schoolteachers pension for the rest of his days, which he would spend in the house she owned when they married."

"The case you're about to hear is not a 'whodunit,'" she told the 14 jurors.

"The case you're about to hear is, rather, a 'what happened.'"

Beckett, 59, was charged a year after his wife, Laura Letts-Beckett, 50, drowned on Upper Arrow Lake near Revelstoke, is a city in southeastern British Columbia in 2010.

He served a term for the Napier City Council from 1998 to 2001 before moving to Canada, where Mrs Letts-Beckett lived, and he worked as a school bus driver.

Peter Beckett vigorously denies claims

Ms Firestone said Beckett took out a number of life insurance policies and accidental-death benefits on his wife between 2007 and 2010, the final one going into effect the month before Mrs Letts-Beckett died.

Ms Firestone said Beckett claimed to have no knowledge of the final insurance policy. But, she said, police found his fingerprints on the document.

Jurors were told Beckett was not immediately a suspect. He described the incident at times as an accident or suicide, Ms Firestone said.

"One by one, certain police officers and civilians began to realize that the version of events painted by Mr Beckett about the events of Aug. 18, 2010, were not accurate," she said.

Beckett was arrested in August 2011.

The first witness called by the Crown on Tuesday was Beth Letts, Mrs Letts-Beckett's mother.

Mrs Letts described to jurors how her daughter met Beckett while travelling in New Zealand in 1995. Five years later, Beckett began making regular trips to Westlock, a town in the province of Alberta, where Letts-Beckett worked as a schoolteacher.

The couple wed in 2003. Mrs Letts said their relationship was a good one at first. She said Beckett eventually became "overbearing and domineering."

Mrs Letts-Beckett filed a police report in September 2007 alleging physical abuse at the hands of Beckett.

Mrs Letts said she was at the Westlock Royal Canadian Mounted Police detachment when her daughter made her statement to police.

"Laura was upset," she said.

"She was crying. He [the officer] kept saying to her, 'Laura, it's not your fault.'

"He suggested to her that she leave the relationship. He said, 'I do not want to be dealing with a homicide later, Laura, and I strongly suggest that you do not go back'."

Mrs Letts said her daughter and Beckett separated for about three months in late-2007, reuniting in January 2008.

While they were separated, she said, Mrs Letts-Beckett came clean to her family about the fact Beckett had been married previously - something to which the Mrs Letts were staunchly opposed.

Mrs Letts said her relationship with her daughter after she reconciled with Beckett consisted only of birthday cards until a phone call on Mother's Day in 2010.

Less than four months later, Beckett called the Letts to say their daughter was dead.

During her cross-examination of Letts, defence lawyer Donna Turko implied Letts-Beckett had been "shunned" or "ex-communicated" by her family, which made her depressed. Mrs Letts denied that allegation, saying she cut off contact with her daughter to reduce stress that was aggravating a medical condition.

Ms Turko also asked Mrs Letts about an alleged rape in her childhood at the hands of a worker on the family farm.

"I don't know that," Mrs Letts replied.

"Laura told me about that several years after it happened."