LONDON, ON -- The defence portrayed Terri-Lynne McClintic as a violent, vengeful, drug-crazed gang member Wednesday at Michael Rafferty's murder trial.

On McClintic's third day in the witness stand, Judge Thomas Heeney ruled that the jury will be free to decide whether McClintic was lying when she testified that she was the one who killed Victoria (Tori) Stafford.

McClintic testified last week that she killed the eight-year-old girl in a fit of repressed rage with hammer blows and kicks after Rafferty had sexually assaulted Stafford.

That directly contradicted a video statement that McClintic made to police on May 24, 2009, when she said Rafferty did the actual killing while she stood by. McClintic stood by her story that she killed Stafford, even when the Crown gave her several opportunities to revise her testimony.

Last week, the jury saw portions of that 2009 videotape, but Heeney cautioned them that they could not consider it as evidence in the case, only as a means to assess McClintic's credibility as a witness.

Heeney ruled Wednesday the jury can again hear a longer portion of the earlier videotape and now consider it as evidence, weighing it against the contradictory statements she made in the trial.

But the judge cautioned the videotape was not sworn court testimony, only a statement made to police.

McClintic sobs throughout the emotional interview and smokes cigarettes. The audio quality is poor, but she describes how Rafferty sexually assaulted Tori, kicked the Woodstock, Ont., girl and then wrapped her head in a garbage bag and hit her with a hammer.

McClintic says she just stood by and watched.

As Rafferty's lawyer, Dirk Derstine, began his questioning of her Wednesday, he drew a portrait of McClintic using letters she'd written while in a youth detention centre about a year before the murder of Tori. McClintic was serving a sentence for robbery and assault.

The letters all used foul gang language and symbols for notorious street gangs such as the Crips in the U.S.

Mumbling in a soft voice, McClintic tried to deny some of Derstine's allegations, arguing she was young and angry at the time.

The letters make frequent reference to a group known as the Murderous Bitches. She also details plans to assault other inmates and exact vengeance against two people who helped convict her.

There were references to a planned victim "who needed to get smashed," and a vow to assault another female inmate who was pregnant.

Derstine suggested to court that McClintic and a friend worked out in prison to intimidate inmates and bully them into handing over drugs.

McClintic has already been convicted of murder in the Stafford case and is serving a life sentence, but is testifying as a Crown witness in the trial of her former boyfriend Rafferty.

He's pleaded not guilty to the first-degree murder, kidnapping and sexual assault causing bodily harm.