WINNIPEG - A 17-year-old St. Lazare boy who pleaded guilty to two counts of second-degree murder in the shotgun killings of his adoptive mother and her four-year-old daughter will not serve adult jail time.

In a Court of Queen's Bench in Brandon Wednesday, the teen -- who was 14 at the time of the killings -- received the maximum seven-year sentence under the Youth Criminal Justice Act, with no credit granted for almost three years spent in custody.

In his ruling, Justice Robert Cummings ordered the teen to spend another four years in custody, with the remaining three years served under conditional supervision in the community.

"I am taking into account the very serious nature of both these offences," Justice Cummings said in his ruling, ordering the maximum youth sentence. "Not one but two murders were committed in a rage. The life of an innocent young girl was taken."

On Aug. 25, 2007, the victims were found dead in their home several kilometres outside the tiny western Manitoba community, about 110 km northwest of Brandon.

According to court documents, the teen's adoptive father arrived at the residence to find his wife and daughter dead and covered by a blanket. He struggled with his adoptive son, who was still in possession of a .22 calibre rifle, before the teen fled. He surrendered to police a short time later.

The Crown had sought an adult sentence for the 17-year-old, which would have meant a minimum sentence of life in prison and no chance of parole for seven years.

The teen made a surprise guilty plea last January, just a week before he was to stand trial on charges of first-degree murder.

In his sentencing, Cummings also noted the teen had no prior criminal history and cited psychological reports that outlined a history of physical and emotional abuse, both in his adoptive home and with his birth parents.

"All of the expert opinion is firm that a youth sentence is most appropriate," Cummings said in his ruling.

Cummings said the teen has expressed willingness to undergo psychological counselling and that such help would be more available if he was sentenced as a youth.

"He was very young at the time and he was striking back at a situation which had been building in him since his very early years," Cummings said.

"He is not a hardened criminal and there are excellent prospects for rehabilitation."

The St. Lazare boy underwent numerous court-order psychological and medical tests after the double slaying to determine whether a medical or chemical imbalance may have played a role in the killings. A Brandon court heard in 2007 the boy's birth mother used cocaine heavily during pregnancy, which may have caused fetal alcohol spectrum disorder in her son.

Court documents stated the teen's birth mother had also been involved in prostitution and that his birth father had been incarcerated for homicide.

jason.halstead@sunmedia.ca