Jane Creba was shot to death on Dec. 26, 2005, as two groups exchanged gunfire amid a crowd of shoppers on Yonge Street. (Canadian Press)

A man accused of killing a Toronto teenager as she shopped on busy Yonge Street on Boxing Day 2005 has pleaded guilty to second-degree murder and has been sentenced to life in prison.

Jeremiah Valentine, 27, entered the plea on Tuesday, just four days short of the fourth anniversary of the death of the 15-year-old Grade 9 student.

He was sentenced to life with no chance of parole for 12 years.

The defence told the court Valentine was surrounded by a gang inside a Foot Locker store when several men lifted their jackets to show they were carrying guns and one demanded his gold chain.

Valentine walked away, but then went outside to confront the men after they were staring at him through the store window, said defence lawyer Edward Sapiano.

"My client is acknowledging his criminal actions, but the facts clearly establish it started with him being the victim of a robbery," Sapiano told the court.

"He stepped up to the plate and accepted full responsibility for his actions."

The Crown told the court that while forensics determined it is "very likely" Valentine fired the bullet that killed Creba, those tests were not definitive.

Creba was caught in the crossfire when rival gangs began firing in a wild shootout on one of the country's busiest streets and one the busiest shopping days of the year. She died a short time later at St. Michael's Hospital.

Earlier this year, four men were acquitted after the Crown said there was no reasonable prospect for a conviction against the four, who were facing manslaughter charges.

One man, however, was convicted in Creba's death.

Jorrell Simpson-Rowe, 21, was found guilty of second-degree murder, two counts of aggravated assault and five weapons charges. Simpson-Rowe, who was 17 at the time of Creba's death, was sentenced to an adult life sentence.

Three others still face charges.

Two men are charged with second-degree murder. A youth is charged with manslaughter.

With files from The Canadian Press