WASHINGTON — A D.C. mother who was severely injured during an arrest for fare evasion has hit a roadblock in her fight against Metro Transit Police more than one year later.

Diamond Rust’s attorney said she cannot sue the Washington Metropolitan Area Transit Authority for alleged excessive force and civil rights violations because metro is protected by law.

It is called the WMATA Compact, which is the transit authority’s guiding document.

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The document has language that Yaida Ford, who is Rust’s attorney, said gives WMATA immunity from being sued even if one of their officers is found guilty of civil rights violations.

“When I look in the mirror all I say is ‘why me?’ Like why did this have to happen,” Rust said during an interview in February 2018.

Metro Transit Police slammed Diamond Rust to the ground, arrested her, and charged her with fare evasion and resisting arrest.

Rust’s face was burst open, several of her teeth were broken, and her knee was fractured.

The incident happened last February off Alabama Avenue in Southeast in front of her two small children.

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Rust’s criminal charges were dismissed in 2018, and her story was at the center of the fight to decriminalize fare evasion in the District.

“There was a lot of stink after I think you covered it and The Post went in on it,” Ford told WUSA9. “Our councilmembers took up the issue of decriminalizing fare evasion. So, we are one step closer. However, in making a victim whole there is just a huge obstacle there.”

Ford said one hurdle Rust is facing is language WMATA’s guiding document.

It reads that the transit authority “shall not be liable for any torts occurring in the performance of a governmental function.”

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“If a citizen has their rights violated by a metro transit officer, WMATA can’t be sued for that,” Ford explained. “It’s something that benefits WMATA but given the fact that what happened to Ms. Rust was so egregious, that law needs to change.”

Ford started a petition to push local lawmakers to make an amendment to the WMATA Compact.

Currently, an alleged victim can only sue individual officers with Metro Transit Police for civil rights violations instead of the agency they work for.