Cheyenne Rose Antoine, 21, pleaded guilty to killing Brittney Gargol in March 2015 after the 18-year-old was found strangled near a landfill in Saskatoon, Saskatchewan.
Her defence team told the court that Antoine and Gargol were drunk and high on marijuana when the argument broke out and that Antoine can not remember killing her friend, although she accepts that she was responsible. That friend dropped a dime on Antoine. The picture of the pair, which was taken hours before Ms Gargol's death, was posted on Antoine's own facebook page and found by the police during a two-year investigation.
According to prosecutors, she had also used Facebook posts to attempt to cover her tracks. "Hope you made it home safe", Antoine had posted on her victim's Facebook wall after the killing.
Antoine said she and Gargol were best friends and were out drinking when they got into an argument, the CBC reported.
After getting drunk, Antoine told the friend that she hit Gargol and strangled her.
At her court appearance Monday, Antoine's lawyer, Lisa Watson, said her client suffered through sexual, emotional and physical abuse as she grew up in foster care, CTV reported.
Facebook photo showing murder weapon helps police to arrest friend-killer
Antoine was initially charged with second-degree murder, but pleaded guilty to manslaughter inside a Saskatoon courtroom.
This put her on the radar of investigators, who found the selfie, and eventually arrested her past year. Antoine says she doesn't remember strangling her friend to death, but doesn't dispute that she killed her. She also played the part of concerned friend, asking Facebook if anyone had seen Gargol. She "has issues...and because of those issues she is unsafe", the CBC reported.
"Most days we can't quit contemplating Brittney, what happened that night, what she more likely than not felt battling for her life", Jennifer Gargol said.
"I'll never forgive myself. I am very, very sorry", she said.
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