A Brooklyn judge dismissed the charges against the homeless woman who took a stolen US Postal Service truck on a joyride Friday and left “vehicular mayhem” in her wake, borough prosecutors said Sunday — as they vowed to push to reverse the decision.

Brooklyn Criminal Court Judge Hilary Gingold ordered Martha Thaxton, 21, committed to a psychiatric facility for theft of the mail truck in Bedford-Stuyvesant after her rampage — and the criminal case against her dropped.

The Brooklyn District Attorney’s Office is now pushing to reverse the decision, a spokesman for the office said Sunday.

“We believe the dismissal was in error and are working with the court to correct it,” DA spokesman Oren Yaniv said in a statement.

According to a transcript of Thaxton’s arraignment, prosecutors requested the psychiatric evaluation — which the judge ruled that, under the law, warrants a dismissal of the current criminal charges pending the outcome of the evaluation.

Lucian Chalfen, spokesman for the state Office of Court Administration, said in an e-mail to The Post on Sunday that prosecutors could have the option of filing the charges again or filing new raps against the suspect. 

Thaxton is accused of jumping behind the wheel of the postal vehicle around 6 p.m. Friday on Fulton Street and Patchen Avenue and taking off — slamming into 10 cars during her wild seven-block ride, police said.

Dramatic footage from the arrest showed Thaxton behind the wheel of the mail truck repeatedly slamming into one parked car as cops try to get to her.

Police finally open the door of the trapped truck and pull her to the ground.

She had been charged with grand larceny, reckless endangerment and other raps in the incident.