MEDICINE Hat, Alta. - Turning down an invitation to help murder a southern Alberta family, Jordan Attfield's own life was threatened to keep him from talking to police, the man told a jury Monday.

Testifying at the murder trial of a 13-year-old girl charged with killing her parents and eight-year-old brother, Attfield also told the jury of an incriminating fragment of phone conversation between who he believed was the accused and her boyfriend, Jeremy Steinke.

"She said 'will you kill them?' And he said 'I'll think about it,' " Attfield said Monday as the triple murder trial entered its third week.

The accused can't be identified under provisions of the Youth Criminal Justice Act. Steinke, now 24, faces the same three first-degree murder charges but has not yet entered a plea and a trial date has yet to be set.

Attfield, 18, told court that he was Steinke's roommate when he accidentally overheard the phone conversation several weeks before the accused's family was found in their blood-soaked house.

Earlier in the trial, the jury heard graphic evidence of how the parents were stabbed multiple times in the basement while the young boy was found lying in his own bed with his throat slit.

Under cross examination from defence lawyer Tim Foster, Attfield admitted Monday that he assumed it was the voice of the accused on the phone call but couldn't say for sure.

Attfield said Steinke then approached him the night of the killings and asked if he would take part.

"He asked me to help him murder those (people)," Attfield said Monday. "And I said 'No, I didn't have it in me.' "

Later that night, Attfield said Steinke phoned him and threatened to kill him if he went to the police, as well as everyone else who might have known his intentions because he wouldn't know which one was "the rat."

"I asked him if he'd just kill a whole bunch of innocent people, and he said 'Yes.' "

Outside court, Foster said the testimony shows his client wasn't involved in the murder plot.

"That's been the theory of the Crown from day one - they've tried to show that my client in some way counselled or agreed to this whole process," said Foster.

"The evidence you've heard so far, in my view, speaks very strongly to the effect that this was (Steinke's) idea and he acted alone."

The young accused has been in the courtroom for the entire trial, but she sits with her back to the gallery benches in a wooden prisoners' box with high back and sides that prevents the public from seeing her reactions or emotions.

Her courtroom attire Monday, including a conservative skirt and blouse, with her hair in a tight ponytail are in stark contrast to the black makeup, short skirts and fishnet stockings in the months before her family's death.

Earlier Monday, court heard testimony from two 14-year-old girls which also offered a stark contrast in the accused's friends.

The first girl, who admitted their friendship had cooled somewhat before the April 2006 crimes, wept uncontrollably on the stand as she talked about how the accused had been grounded and unable to accompany her on the school bus.

The two girls even had a text-message conversation the night of the killings, when the accused was asked if she would like to go to the mall or hang out the next day. The answer was a curt "I can't" before signing off, the friend testified.

The other friend showed no emotion in court over the alleged crimes, and even admitted to lawyers that she was tough and didn't scare easily - even when she was initially charged with murder.

She told the jury of how she had run away from her foster home and was getting a ride from another friend to Saskatchewan when the accused and Steinke joined them and travelled in the box part of the pickup truck.

She testified that immediately after being arrested, the accused wondered if Steinke, nearly twice her age, would be charged with rape.

And the friend recalled how all four girls arrested that morning joked and laughed about how they should accuse the arresting officer of sexually assaulting the pre-teen instead.

The friend also said she read a newspaper article about the triple murder and passed it to the accused and Steinke.

"They were reading it and pointing things out in it," she told the court.

She also said that once the accused and Steinke had been taken away by police, the remaining three girls took razor blades that they had concealed and began cutting up the back of the police car.

And they concocted a false story about going on a camping trip.