A courtroom sketch shows Jeremy Steinke testifying in his own defence Monday at his first-degree murder trial in Calgary. Steinke said his girlfriend, not he, killed her eight-year-old brother. ((CBC))

An Alberta man admitted to a jury Monday that he killed his girlfriend's parents in an unplanned attack, but said he had nothing to do with the stabbing death of her eight-year-old brother.

Wearing a wrinkled white dress shirt, Jeremy Steinke, 25, took the stand for almost four hours Monday morning as his first-degree murder trial entered its third week.

He testified that he went to the girl's family home in Medicine Hat, Alta., in April 2006 because she had phoned to ask for his help in sneaking out that night to see him. Steinke's version of events contradicts the Crown's assertion that he and his girlfriend planned the crime so they could run away together.

Steinke said he was drunk and high on cocaine and ecstasy as he waited outside the four-level split house, but when the girl didn't appear, he entered through a basement window.

He testified that he encountered the girl's mother, who screamed when she saw him. Steinke said he pulled out a knife he always carried for protection, and stabbed her once in the abdomen.

Her husband then came barrelling down the stairs, picked up a screwdriver and attacked Steinke, jabbing him in the eye. The two struggled, then Steinke stabbed him too, according to the testimony. Steinke said he couldn't recall how many times he wounded the couple.

"I didn't know what was going on. I was just panicking, freaking out," he testified.

The jury has heard from a medical examiner who said the woman was stabbed 12 times, while her husband suffered 24 knife wounds.

The victims cannot be named to protect the identity of the girlfriend, who was 12 at the time of the killings.

Girlfriend slit brother's throat, alleges accused

The accused said he then went upstairs where his girlfriend met him in the kitchen with a kiss. Steinke said he waited there while she went to the home's next level, where he could hear a conversation but not what was being said.

"That's when I looked in [the boy's] room and seen her cut his throat," Steinke told the jury. "He was lying on his back on the bed and she was standing over him."


A Medicine Hat couple and their son were found slain in their southern Alberta home in April 2006. ((CBC))

Steinke insisted repeatedly that he didn't touch the boy.

He testified that he was shocked by the scene and had to leave the house, adding that he threw up after driving away.

"Did you go over there with the intention of killing?" defence lawyer Alain Hepner asked.

"No, I did not," Steinke answered. "I went over there with the intention to pick [the girl] up and return to my residence."

In his opening argument Monday, Hepner said his client's crime wasn't premeditated. A first-degree murder conviction requires an intent or plan to kill.

Earlier, Steinke, who said he's taking medication for paranoid schizophrenia and depression, told the court about his troubled childhood, how he grew up with an alcoholic mother, and was physically abused by her husbands and boyfriends.

The Crown is scheduled to begin its cross-examination of Steinke on Tuesday morning.

Graphic evidence presented in court

The Crown wrapped up its case on Thursday after calling a total of 48 witnesses over nine days.

The six-man, six-woman Calgary jury has struggled with graphic evidence entered during the trial, including a bloody crime scene and autopsy photos showing the victims and their dozens of stab wounds. During most of the Crown's case, Steinke kept his head lowered and stared at the floor, showing little emotion.

The jury has also heard an audio recording of a conversation between Steinke and an undercover officer in which the accused is heard joking and bragging about the triple slaying.

When questioned about that by Hepner on Monday, Steinke said it was "all talk" and that he was only trying to act macho to fit in with someone he thought was a criminal.

Steinke also dismissed online messages between him and his girlfriend that talked about killing people as just joking around.

If found guilty, he faces a life sentence with a minimum of 25 years in prison.

The girl, who was found guilty last year of three counts of first-degree murder, is serving a maximum 10-year sentence for young offenders.

With files from Scott Dippel, Canadian Press