In a video shared online, Ms Waters parked her SUV and said she intervened to see what Los Angeles Police Department (LAPD) officers were doing when they pulled a black man over.
The black Democrat told the person videoing that “they stopped a brother so I stopped to see what they [the LAPD] were doing”.
She added that police had threatened her with a ticket, and said: “They say I’m in the wrong place”
“They’re going to give me a ticket, but that’s okay, as long as I watch them,” added the congresswoman.
She was then seen walking back towards the police, as another person behind the camera says “you gotta do what you gotta do, make sure”.
Ms Walters responds with “I will”, as the video ends.
Thousands have since watched the 15-second clip on Twitter, where it was shared on Sunday.
It comes almost two months after nationwide demonstrations against police brutality and systemic racism sparked by the death of an unarmed black man, George Floyd, in Minneapolis police custody on Memorial Day.
The Independent has contacted Los Angeles’s police department for comment.