The victim, Sienna Edwards, made a chilling 911 call shortly before her fall, in which another woman could be heard saying, "You're not going to leave here alive."
Sienna Edwards died Thursday after falling 14 stories from the balcony of an apartment in the Bronx.
Police now believe that the 20-year-old fell while trying to escape a group of women who were threatening to kill her, after apparently mistaking her for someone else.
Edwards' boyfriend told reporters she had gone to the home as a favor for a male acquaintance, who needed help delivering birthday presents to his 3-year-old daughter.
The incident happened Thursday night at the Clinton Towers Complex in the Bronx. Edwards went to the building on East 179th Street with her boyfriend to deliver a cake for his daughter's third birthday.
The unidentified man waited in the lobby because the child's mother has a restraining order against him.
Upstairs, friends and police say Edwards ran into trouble. The apartment was occupied by her boyfriend's ex, her sister, and a friend.
Edwards first called relatives for help, and then also called 911.
The police commissioner says the 20-year-old didn't speak to the dispatcher, but left the line open.
Police triangulated the cell phone signal and narrowed Edwards' location to within a block, but by then a building resident called to report someone had fallen to their death.
Police say they were originally told Edwards went into the apartment and committed suicide.
Police arrested the little girl's mother, Kenya Edmonds, on murder and manslaughter charges late Friday.
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