Defendant Noah Gaston leaves court on Thursday after Justice Michaela Murphy granted the defense’s motion for a mistrial in his murder case. (Gregory Rec / Portland Press Herald)

A judge declared a mistrial Thursday in the case of a Windham man who is charged with murder for fatally shooting his wife. 

Noah Gaston’s jury trial had barely started this week when Superior Court Justice Michaela Murphy abruptly halted testimony. The state’s chief medical examiner was supposed to take the witness stand Tuesday, but that morning he told prosecutors that he had changed his opinion about the angle of the gunshot wound that killed Alicia Gaston. 

Maine Chief Medical Examiner Mark Flomenbaum conducted the autopsy after the 2016 shooting, but Assistant Attorney General Meg Elam said his conclusion apparently changed Tuesday when he saw a photograph of the wound that was about to be presented to the jury. 

That forensic evidence was expected to play a significant role in arguments about how close Noah Gaston was to his wife when he shot her, and whether he could have mistaken her for an intruder. 

Murphy ordered a new trial in front of a different jury, although it was not immediately clear how soon that could be done. The case has been repeatedly delayed in the three years since the shooting. 

“Both sides in this case either missed or misapprehended evidence that bears directly on what they both agree to be a critical issue, namely where Mrs. Gaston was positioned on the stairway when she was shot and killed,” Murphy said. “To simply allow the trial to go forward given the uncertainty created by this new information would cast a shadow on the verdict reached by the jury.” 

The judge did not place blame on either side for the error, and the parties quickly left the courtroom upon her announcement. Gaston, still wearing his gold wedding band, showed no emotion as he walked out with the guards. Family members of both husband and wife also left the courthouse without commenting to the media. 

Defense attorneys Robert Andrews and James Mason spoke to reporters outside the courthouse. Andrews said they would be looking for their own experts to analyze the forensic evidence, but he could not speculate about their next steps without a full explanation from the medical examiner. 

“We’re all disappointed in the sense that this trial had to end,” Andrews said. “It’s been a long road for everyone in this case, for everyone. We don’t want to downplay anyone’s expectations, but it’s been hard on everyone, and it’s going to continue to be hard on everyone for a little while longer until this issue is resolved.” 

TRIAL PAUSES UNEXPECTEDLY 

Elam declined to comment as she left the courthouse. A spokesman for the Maine Attorney General’s Office said only that the case is ongoing. The Medical Examiner’s Office also declined to comment. 

Alicia Gaston, 34, died from a single shot from a shotgun in the stairwell of the family’s Windham home on Jan. 14, 2016. Her husband has said he thought she was an intruder when he fired the gun, but prosecutors have argued that he intended to kill her. Gaston, 36, is charged with murder and manslaughter. He has been held without bail at the Cumberland County Jail since he was arrested more than three years ago, and he will remain in custody. 

The trial began Monday with opening arguments and emotional testimony, but the judge unexpectedly paused the trial Tuesday after a closed-door conference with the attorneys. The reason for the delay did not become clear until Thursday morning, when the judge heard oral arguments on the defense motion for a mistrial. 

Flomenbaum, the state’s chief medical examiner, told prosecutors Tuesday morning that he had changed his opinion about the direction of the shotgun wound. He was scheduled to testify in the trial that day. 

STATE: ‘IT’S STILL A MURDER’ 

Court documents show Flomenbaum conducted the autopsy on Alicia Gaston and he released a report within days of her death that said the wound path was “very slightly downward.” 

Flomenbaum then placed a rod in a forensic dummy to simulate the wound path. Investigators, including a ballistics expert, brought that dummy to the Gaston house. They used it to estimate that Alicia Gaston was near the top of the staircase when she was shot. 

Elam told the court Thursday that it appeared Flomenbaum changed his opinion Tuesday when he saw a photograph of the wound that had been prepared as a trial exhibit. It is not clear whether he took the photograph or if he had seen it before, and Elam did not say what about the photograph changed the medical examiner’s opinion. 

But Flomenbaum told the prosecutors he now believed the path could have been at an angle of as much as 45 degrees. That calculation could mean Alicia Gaston was farther down the staircase when she was shot. 

The defense lawyers argued Thursday that their preparation for trial would have been different with the new information, and they already told the jury they would not challenge the state’s forensic evidence. Changing their approach would have undermined their credibility and jeopardized Gaston’s right to a fair trial, Andrews said. 

The state countered that the medical examiner’s testimony does not need to change, and suggested the judge prohibit him from sharing the new opinion in court. Prosecutors said Alicia Gaston’s position at the top of the stairs was supported by other forensic evidence, like blood splatter and lead residue. 

“It’s still a murder from the state’s point of view,” Elam said. 

The judge did not set a date for a new trial, but she told the attorneys she expected them to make it a priority. 

“The court is very mindful that the family of Alicia Gaston has waited a very long time for this trial, and also that the defendant has been in custody for a very long time awaiting trial,” Murphy said.