AUBURN – Prosecutors dropped a drunken driving charge Monday against local police officer Mitchell Sweetser, shortly before his trial was set to get under way.

Assistant District Attorney Richard Beauchesne said his office expects to file new charges stemming from further investigation of a November accident involving Sweetser in which the other driver has died.

A judge dismissed a jury in Androscoggin County Superior Court with an apology and cited the District Attorney’s Office for not having notified the court of the need to possibly postpone the case.

After court was adjourned, Beauchesne apologized to Sweetser, 42, and his attorney, Leonard Sharon.

Beauchesne said he couldn’t comment on specifics behind the dismissal. Afterward, he filed notice with the clerk’s office to dismiss the charge with the notation: “investigation incomplete.”

The case was transferred to the Maine Attorney General’s Office to avoid possible conflict of interest. Deputy Attorney General William Stokes, who heads up the criminal division, said Monday that he hadn’t talked in weeks to Beauchesne, who works out of the Oxford County office of the area district attorney.

Beauchesne and Sharon met with Justice Thomas Delahanty II in his chambers intermittently for about an hour to discuss last-minute concerns before the jury was called into the courtroom.

Sharon said later Monday that one of the issues leading to the dropped charges was the recent death of the driver of the other vehicle involved in the crash.

Nathan M. Taylor, 25, of Auburn was driving a 2005 Nissan pickup truck on Union Street bypass when Sweetser, driving a rented 2002 Dodge, reportedly ran a red light on Hampshire Street at 11:30 p.m. on Nov. 21 and crashed into Taylor’s truck, hitting the driver’s side. A police report said Sweetser apparently fell asleep behind the wheel.

Taylor complained of soreness, but declined to be treated. His passenger, Amber Cyr, 20, of Hartford, also declined treatment.

Sharon said an autopsy was performed on Taylor, but efforts by the court to learn the cause of his death Monday morning before the trial were unsuccessful.

Another issue raised by Beauchesne was whether a medical expert hired by Sweetser could testify about blood-alcohol results collected and tested by the hospital where Sweetser was treated, Sharon said. The results matched exactly the results from tests undertaken by police two hours later, Sharon said. That called into question their accuracy, a point Sharon planned to raise during the trial, he said.

Beauchesne argued the expert shouldn’t be allowed to refer to the hospital test results without learning more about whether blood drawing and testing procedures were properly followed by personnel at Central Maine Medical Center in Lewiston, Sharon said.

His blood-alcohol level was recorded at .19 percent, more than twice the legal driving limit. He was charged with criminal operating under the influence, a Class D misdemeanor, punishable by up to 364 days in jail.

Sharon said his client, who was placed on administrative leave without pay after the accident, is struggling financially. He’s a part owner of used car dealership in Lewiston, Sharon said.

Sweetser’s head crashed through the passenger window of the car he was driving and he suffered a serious head wound. He also has a lingering shoulder injury. Sharon said Sweetser is physically able to return to work.

Sweetser had hoped to get the charge behind him “so he can get on with his life,” Sharon said. “We believe these issues could have been dealt with a while ago and saved the jury and court a lot of time,” he said.