Despite further tests by the city's medical examiner, police admitted Thursday they may never know exactly what killed Liana White, 29, whose badly decomposed body was found in a ditch northwest of the city last weekend.

White's husband, Michael, 28, was charged earlier this week with second-degree murder and comitting an indignity to a dead body after a search team he was involved in found her body in a wooded area near a rural intersection.

White's body was so badly decomposed when it was discovered last Sunday investigators had to use dental records to determine her identity and that advanced state of decay has also hampered the medical examiner in pinpointing an exact cause of death.

Wounds, some of which may be so tiny as to be obvious only to the medical examiner, helped determine that White died as the result of violence and that her death was a homicide, said police spokesman Dean Parthenis.

But the wounds don't tell investigators how Liana White, formerly of Kelowna, B.C., died, Parthenis said.

"It doesn't necessarily mean the wounds they've located have contributed to the death," said Parthenis.

"But it gives them a potential idea of what the victim may have gone through," he added.

Police won't be specific about what kind of wounds White suffered and where they were on her body.

Parthenis also said some of the clues into what killed her were lost.

"It made it very difficult for the medical examiner to find certain signs, clues, that would point to a more definitive cause," Parthenis said.

Another way the medical examiner officially determined that White's death was a homicide was that there was no natural causes that contributed to her death.

It may seem strange that White's husband was charged with murder earlier this week even though investigators hadn't yet determined what may have killed her.

But there is other information that could lead to charges being laid without knowing the cause of death, said Parthenis.

"That could be evidence, for example, that was gathered from the scene where the SUV was found, from the site of where the body was located and from the residence," he said.

"There can be enough information that would point investigators in the direction of being able to lay charges, without this other information necessarily being finalized."

Liana White's story has gripped the Alberta capital ever since her Ford Explorer was found abandoned just blocks from her home on July 12. Her purse, shoes and cellphone were scattered nearby.

Michael White, originally from Mar, Ont., made several emotional public appeals for help in his wife's disappearance, and finally expressing frustration with the pace of the police search for his wife, started looking for her last week with the help of family and friends.

Investigators are still trying to determine a possible motive and are checking into reports the couple had some financial trouble, said Parthenis.

Published reports say the couple was heavily in debt with liens on two vehicles and a $166,000 mortgage on a $170,000 house.

Meanwhile, the Alberta Union of Provincial Employees announced Thursday it had established a trust fund for White's three-year-old daughter, Ashley.

Liana White's disappearance and the subsequent murder charges filed against her husband have upset colleagues at the Royal Alexandra Hospital where she was a clerk in the neonatal intensive care unit.

"Liana was part of the AUPE family and our members at the Royal Alex want to do something in her memory for her little girl," said union president Dan MacLennan.

"The members want to do this because they feel Liana's daughter Ashley is going to need some support later in her life," said Patricia Newel, the union's membership services officer.

"They want to show Ashley that her mother was loved very much by her co-workers," she added.