Brutal arrest video of 16-year-old goes viral, sparks outrage. This is what the cops say about it.

Police arrested a 16-year-old girl in Stoughton, Massachusetts, last week, and a portion of the teen's arrest was captured on camera.

What was caught on camera went viral on social media, and the Stoughton Police Department found themselves under fire for the hard-to-watch video, which was shot outside of a Stoughton homeless shelter, according to WBTS-TV.

According to the station, police were initially called to the shelter after employees were threatened with violence.

Now police are reviewing officers' roles in the arrest.

What happened in the video?

What prompted the unnamed teen's arrest in the video is unclear, but the teen can be seen being aggressive with police officers out of the gate — swinging and shoving at officers who attempt to restrain her.

Throughout the incident, it is apparent that the teen refused to follow the officers' commands.

Officers ended up subduing the teen, slamming her on the ground, and tasing her as she shouts.

One witness, Patricia Coutts, told WBTS that the arrest was "ugly."

"I saw them slam her face in the ground," Coutts said. "[A cop put] his knee in her, and then they had the cuffs on her, but they kept tasing her, and that's what upset me."

"Was she wrong? A little bit on her side. Were the police wrong? A little bit on their side," Coutts added. "I can see their need to protect themselves, but she was a 16-year-old girl. I just thought it was so much."

Bob Sinclair, another eyewitness who lives next door to the shelter and watched the scene play out, confirmed that the teen was simply not following the direction of the officers.

"She wasn't cooperating," Sinclair explained. "They had their stun guns out, and they told her to stop, she didn't stop, they stunned her."

Sinclair added, "If a police officer tells you to stop, you stop. If you don't, there's going to be a problem."

You can watch a portion of the encounter in the video below.

(Content warning: Rough language, violence):

What are police saying?

According to WBTS, police said that a patrolman and a supervisor — who was later taken to a hospital to be checked out — were punched, scratched, and slapped during the scuffle.

In a statement, the Stoughton Police Department said that officers respond frequently to the homeless shelter in question and had also responded to three separate incidents within 24 hours of the viral video, the outlet reported.

"When it comes to a violent altercation, we [cannot] just call a time out to ask for identification to determine the offending parties [sic] age," Stoughton Police Lt. John Bonney wrote in a statement. "As it relates to use of force, it is dictated by the offending party regardless of age or gender. Once you are told you are under arrest you can not resist or become assaultive."

Police are investigating the incident, according to the station.