The woman, identified only as Ms. Cooper, says her daughter was initially suspended for 10 days but was then expelled following the incident on Jan. 10, the outlet says.
The video shows the 15-year-old student being stabbed nearly a dozen times inside a bathroom stall at the high school.
Charging documents obtained by WBAL say the victim was dating the suspect's ex-boyfriend, and that the suspect followed the pair right before the stabbing.
Cooper says her daughter heard commotion in the stall next to her and began filming, not knowing exactly what was going on. When she realized, she ran out of the bathroom, yelling, Cooper tells FOX45.
A statement issued from school officials to FOX45 reads, in part: "Our schools will also issue serious consequences to students who participate as bystanders and record and/or take photos while a serious incident is occurring."
Click here for more from FOX45.
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