Ruby Jones' attorney, Damario Solomon-Simmons, released this disturbing footage Tuesday not long before filing a lawsuit against the City of Oklahoma City and the 3 police officers involved with the August, 2020 encounter at her OKC home.

In docs, obtained by TMZ, Ruby claims she suffered a broken right arm due to the officers' "use of excessive force" when they came to arrest her mentally ill son, Chauncey.

The body cam footage shows the officers arriving with an arrest warrant for Chauncey, who officers alleged had called in a bomb threat at the Red Rock Behavioral Center. Cops said they traced the call back to Ruby's home.

But, in docs, Ruby claims she met the officers at the front door and they asked for consent to enter, but she refused. She also claims cops refused to provide proof of a warrant authorizing entry into her home.

You can see in the body cam footage ... cops threatened her with jail if she didn't get out of their way. When she didn't allow them in, they tried to handcuff her while screaming, "Let me see your f***ing hands."

According to the suit, Ruby pled with cops not to shoot Chauncey because he suffers from bipolar disorder and did not have a gun. In the video she repeatedly tells the cops Chauncey isn't armed ... but they tell her, "You're fixin' to go sit in the car."

When she refused to go outside, Ruby alleges they "grabbed her arm, and forcefully yanked her out of the bedroom." The video backs that up, and she also told the officers she suffers from heart disease. In the docs, she claims they broke her arm after throwing her against a mirror and handcuffing her.