EMBED >More News Videos A family is speaking out after video shows a woman being hit by a Chester police officer as reported by Christie Ileto during Action News at 11 on March 18, 2019.

EMBED >More News Videos FULL VIDEO: Chester police are investigating a violent confrontation involving an officer during a house party on Saturday, March 16, 2019.

CHESTER, Pa. (WPVI) -- The family of a woman who is the subject of an arrest captured on a video that has since gone viral has spoken to Action News about the incident.He tells Action News his 20-year-old granddaughter is still behind bars Monday night."I only talked to her briefly this afternoon," said a man who identified himself as Dominique Difiore's grandfather.Chester police say she assaulted a sergeant over the weekend after she and three other people tried to crash a house party near Widner University. All four of them had initially been turned away from the festivities when police arrived to break up the melee."It is what it is, she was partying and that's all I'm going to say," Difiore said. "There's no reason for that."Difiore says he's seen the now viral video of his daughter being hit by that officer after she allegedly hit him first."There's no reason for it. It's unacceptable. To use that kind of force. Come on! She's a kid!" he says.Chester police say the St. Patrick's Day festivities has become an annual event off campus that they try to monitor, and the weekend incident is under investigation.The department tells Action News they've reviewed more footage that details what led up to the now viral incident, are still looking for more.Difiore is facing aggravated assault, among other charges, and the three other individuals, Shawn Connelly, Tess Herman, and Jaylene Westfall, are also facing assault charges.We reached out to her attorney but didn't hear back.Top brass say as they continue to review video, more arrests could be pending.