Briscoe's ex-girlfriend denied knowing slain prostitute

The defence is questioning the credibility of a key witness for the prosecution in Michael Briscoe's murder trialBriscoe's ex-girlfriend Stephanie Bird.

Briscoe is on trial for first-degree murder in the April 2005 slayings of Edmonton prostitute Ellie May Meyer and teenager Nina Courtepatte.

Bird, 24,testified on Wednesday that she saw Briscoe and his friend Joseph Laboucan beating Meyer in a farmer's fieldeast of Edmonton in April 2005.

She also testified that Briscoe was involved in killing Courtepatte, 13, two days later.

On Thursday, Briscoe's lawyer Charles Davisonsaid Bird's testimony conflicted with what she told police previously.

Bird denied being involved in Meyer's death but that changed, Davison contended, when police told her she would be charged with murder.

Davison challenged Bird on the stand, telling her that she concocted a story to avoid prosecution by using snippets of information from police an accusation she denied.

Bird denied knowing Meyer

Wiretap evidence of Bird's phone calls was also played in court on Thursday where she is heard saying she had never seen or met Meyer.

In 2007, Bird was being held at the Edmonton Young Offenders Centre in connection to the Courtepatte case when police told her she was also a suspect in Meyer's slaying.

On one recording, Bird tells a woman: "They showed me a picture of this chick. I've never seen her before."

In another call two weeks later, Bird is asked if she is being accused of killing Ellie May Meyer.

"That's the name," Bird responds. "But I've never seen her."

She made the same denial in a phone call to a friend two months later and in another call recorded last year.

Bird is serving a life sentence for her role in Courtepatte's murder after the Supreme Court of Canada upgraded her original manslaughter conviction to first-degree murder in 2009.

Laboucan has already been convicted of first-degree murder in the deaths of Meyer and Courtepatte.