Surveillance video taken from inside of a school shows Chicago police officers drag a student down a flight of stairs at Marshall High School then punch and shock her with a taser multiple times.
The officers, Johnnie Pierre and Sherry Tripp, claim 16-year-old Dnigma Howard initiated the incident on January 29.
They originally charged her with two felony counts of aggravated battery, according to the Chicago Sun Times.
But new video evidence appears to contradict their story.
The video shows the officers holding Howard down while stepping on her chest after dragging her down a flight of stairs.
Her father, who had been asked to come to the school to pick her up, witnessed the incident, according to a lawsuit filed by Howard's attorney, Andrew Stroth.
"The Board of Education and CPD continue to fail our children. An unarmed 16-year-old girl was beaten, kicked, punched and tasered by officers," Stroth said.
The lawsuit accuses Chicago Public Schools, the city and officers Pierre and Tripp of violating Howard's civil rights.
The criminal charges filed against Howard were dropped less than a week after the incident "in the interest of justice," prosecutors said.
At an initial court hearing, prosecutors stated the officer Pierre and Tripp were called to escort Dnigma Howard off the school's premises following a suspension.
The officers claimed she refused to leave then kicked, bit and spit at them, which led the three of them to fall down a flight of stairs.
The fall, they said, caused all three of them to be treated at a local hospital.
In arrest report, the officers wrote that Howard "became irate and initiated a physical altercation with the officers."
Howard's attorney says the officers lied.
"Those officers filed a false statement," Stroth said.
"Their statements are completely untrue and are completely contradicted by what is shown on the video. The saving grace for Dnigma is that this was caught on camera."
Previous footage of the incident, which was recorded on a cellphone by a fellow student, showed the officers using a taser on Howard.
It did not show the events leading up to that point.
The new video shows officers standing by Howard as she speaks to another student and gives her a hug.
She begins walking away from the stairwell when suddenly an officer grabs and then drags her down a light of stairs.
Another security camera captures one of the officers pulling Dnigma down the bottom flight of stairs by her leg as another officer falls while holding onto her from behind.
As she tumbles to the floor near a metal detector, one officer steps on her chest as the other one punches her.
Then she is shocked with a taser.
Laurentio Howard, Dnigma's father, can be seen at the end of the video standing near the confrontation.
According to the lawsuit, officers did not allow him to intervene or deescalate the situation.
Chicago Public Schools spokeswoman Emily Bolton said the school district's inspector general is investigating.
"We are deeply disturbed and troubled by this incident, which has no place in our schools," she said in a statement.
Footage from the officers' body cameras have not been made public.
Video taken by the student can be seen below.