Dashcam video shows a trooper trying to make his way to the protests in the westbound lanes of the Vine Street Expressway back on June 1.
He eventually pulls over, unable to make it past the stopped cars.
RELATED: Police fire tear gas on I-676 as Philadelphia protests continue
A few minutes later video shows demonstrators start marching down the eastbound lanes, some walking on the median.
Soon protesters hop onto the westbound side.
That's where someone appears to spray something on the patrol car's windshield.
Dozens of demonstrators were arrested after tear gas was deployed.
RELATED: Philadelphia protesters gassed, maced on I-676 taking legal action
Action News spoke with one of the protesters planning to take legal action.
Katharine Miller, who was captured on video being pepper sprayed by police, says the demonstration started off peaceful and quickly turned violent.
"All of a sudden people started screaming and sprinting. There was clearly more gas behind us and there was just nowhere to go," she said.
All I could think was this person is going to get murdered. We've all seen this video. So I jumped down and knelt in front of him," Miller says.
The officer in the video sprays Miller, pulls down the goggles of the woman next to her before spraying her. He then confronts Hough, who also hit with rubber bullets while trying to dodge the pepper spray.
"There was no reason for the blatant use of force," says Riley Ross with Mincey Fitzpatrick Ross, LLC.
Ross and his firm is representing more than a dozen protesters.
The police response is still under investigation.