Home video of a girl fight at Strawberry Mansion High School was posted on the popular internet site, YouTube. The girls go after each other as a camera records inside the cafeteria.
Philadelphia police acknowledged they are dealing with a growing problem of teenage girls committing crimes against teenage girls.
"It clearly appears that the level of violence has escalated when it comes to young girls. What the reasons are behind that, sociologists may have to answer. We're going to investigate it and hold those people accountable," said Capt. Ben Naish.
Among the cases: Police are working to stop groups of girls from harassing and robbing young subway riders on the Broad Street Subway.
In a separate case, a 16-year-old was arrested for slashing 15-year-old Shakia West outside West Philadelphia High on Monday. Other teens told Action News that they always stay on the lookout for girls looking to do them harm.
"It's fighting. My friend got her cell phone taken and her bag," said eighth grader Masari Brown.
The Philadelphia School District is working with police to gather what they call "juvenile intelligence." That effort includes watching the internet for evidence.
"Clearly to prevent violence and to investigate matters that do occur, and to make sure we are taking swift and appropriate action," said school district spokesperson James Golden.
Commissioner Ramsey said that while it is shocking when it's girls involved in such violent crimes, he is committed to reducing all violence involving young people, male or female.