Nina Courtepatte's body was discovered on Edmonton Springs Golf Course west of the city in April 2005. ((CBC))

A young woman testifying at a first-degree murder trial for the slaying of a 13-year-old girl in Edmonton said she had cruised Whyte Avenue with the accused in the case, looking for a second victim.

Michael Briscoe, 36, and Joseph Laboucan, 21, are on trial for the kidnapping, aggravated sexual assault and first-degree murder of Nina Courtepatte in April 2005.

The 18-year-old witness who testified Friday also faces the same charges, but has yet to go to trial. She can't be named under the Youth Criminal Justice Act because she was a youth at the time she allegedly committed the crimes.

The witness testified Monday that she, Laboucan and Briscoe dropped off two others after the attack on Courtepatte and then drove along Whyte Avenue, a popular strip with bars and restaurants.

"Joe said it was such an adrenaline rush, and he asks, 'Do you know anybody else on Whyte Avenue?' "

The witness said she told Laboucan about another girl, andhe responded that he knew her, saying"She trusts me." But theydidn'tfindthe girl they were looking for, the witnesstestified.

Witness said she was 'sketching out'

Under cross-examination, the witness saidBriscoe may not have not been in the car at the time of the discussion, but out finding food.

Laboucan's lawyer questioned the 18-year-old's recollection of events, asking her aboutdrug use.The witness admittedshe had used "everything except heroin" around the time Courtepatte was killed.

"I couldn't think straight. I was sketching out. I thought I saw things that weren't there," she said.

When Laboucan's lawyer asked the witness if she lied a lot, she replied, "Sometimes." Shealso testified that she was once told by a doctor that she had sociopathic tendencies, though she had never been formally tested for them.

Grisly attack on Courtepatte described

On Friday, the witness described being with a group, including the two men on trial, thatpicked up Courtepatte and her friend at West Edmonton Mall.

Laboucan and a younger man sexually assaulted Courtepatte in a deserted field outside Edmonton, she said.Courtepatte was choked with a wrench, hit with a sledgehammer and eventually stabbed with one of the throwing knives that were in a backpack, the witness testified.

The woman told the court she also stabbed Courtepatte with one of the knives, but she thought the girl was dead at the time because she had stopped moving and gurgling.

5 people charged in Courtepatte's death

Courtepatte's bruised and bloody body was found on the Edmonton Springs Golf Course in April 2005.

Briscoe and Laboucan are being tried before a judge alone in Alberta's Court of Queen's Bench. The trial is expected to last a month.

They are among five people charged with the girl's murder, but unlike the other three, they were adults at the time of her death.

A 19-year-old man has already pleaded guilty to first-degree murder. Two young women, including the 18-year-old witness and a 19-year-old, are charged with kidnapping, aggravated sexual assault and first-degree murder, but haven't yet gone to trial.

The trio can't be named under the provisions of the Youth Criminal Justice Act.