The former police officer known as "Agent 728" was in court Tuesday for the beginning of her assault trial.

Stefanie Trudeau was charged in March 2014 with assault after being caught on video making a violent arrest in October 2012, and then insulting the people she was trying to arrest.

She tried to arrest a man who was living at a Papineau Ave. apartment near the corner of Mount Royal Ave., but he resisted arrest. She is accused of abusing her power because she didn’t have the right to arrest him.

The first witness is one of the men who lived at the apartment.

The court saw video of the arrest Tuesday morning. There were five different cameras filming from five different angles, so the prosecution is going through all the videos to determine the position of everyone who was present that night.

In the video, an artist named Rudi Occhietti is seen getting handcuffed by Trudeau for allegedly holding a beer on the sidewalk next to the Papineau Ave. studio he shares with others.

Occhietti told the court how Trudeau ordered him to show ID, and he asked her why. Trudeau, it's alleged, pulled him by his collar and threw him on the sidewalk.

Under cross-examination, the witness admitted it was illegal to drink on the sidewalk, but he maintains that Officer Trudeau never told him what he did wrong before she pushed him to the ground.

With Occhietti handcuffed, he claims he was kicked and punched repeatedly. As video captured the incident, Trudeau and her partner proceeded to enter the studio, despite protests by the occupants.

Trudeau and her partner are seen grabbing and trying to arrest a man named Serge Lavoie inside the studio, again, as his friends caught the incident on camera. 

The prosecution claimed that arrest was unjustified and therefore Trudeau's use of force was illegal. She was charged with simple assault against Lavoie, who can be heard in video footage screaming in the stairs.

Lavoie and three others were arrested and charged with obstruction that night, but the charges were later dropped. 

Trudeau said she plans to argue that the charges against her should also be dropped, because it took too long to take the case to trial. 

Trudeau was escorted into the courthouse by Montreal police Tuesday as striking public sector workers demonstrated outside the building.

The case resumes Friday.