Middlesex prosecutors have dropped a kidnapping charge against state Representative Carlos Henriquez, but are still pursuing other charges against the Dorchester lawmaker for an alleged assault on his former girlfriend.

The office of Middlesex District Attorney Gerard T. Leone Jr. released a brief statement Thursday night outlining their decision.

“Based on our investigative development of the facts in this case, applying the relevant law, and considering all the attendant facts and circumstances, including the best interests of the victim, we have made a ­decision to prosecute the charges at District Court without a kidnapping charge,” the statement read.

Stephanie Chelf Guyotte, a spokeswoman for Leone, said prosecutors are charging ­Henriquez with assault and battery, larceny under $250, and witness intimidation.

Jeffrey Denner, a lawyer for the state representative, said Thursday night that he expects his client will be vindicated.

“We will continue to defend the case zealously, and it certainly is our hope and expectation that he will ultimately prevail on all of the charges at the end of the day,” Denner said.

Henriquez, 35, a first-term lawmaker, could not be reached for comment.

He is accused of punching and choking his girlfriend, Katherine Gonzalves, and ­refused to let her out of the car that he picked her up in at her mother’s home in Arlington during the early morning hours of July 8.

He pleaded not guilty in July to charges stemming from the incident in separate cases in Middlesex and Suffolk counties. The case spans two counties ­because the incident began in Middlesex County, where Henriquez picked up Gonzalves, and concluded in Suffolk County, where she ultimately exited his vehicle.

Henriquez has called the charges against him “completely untrue,” while Gonzalves has publicly stated that she told ­police the truth about what happened.

Henriquez was initially charged in Suffolk County with assault and kidnapping offenses, among other violations. Jake Wark, a spokesman for Suffolk District Attorney Daniel F. Conley, could not say on Thursday night whether prosecutors are still planning to bring the kidnapping charge in that county, but said that the case will be adjudicated in District Court.

Neither Gonzalves nor her attorney could be reached for comment Thursday night.

At a community meeting last month, Henriquez rejected a call for his resignation from a state Senate candidate and also said he would not resolve the pending cases with any type of plea deal.

“I can’t plead to something I’m innocent of,” he said at the time.