A state board that investigates complaints against attorneys is recommending a one-month suspension for a Martha’s Vineyard prosecutor, after a finding that she abused her prosecutorial power.

A memorandum released Monday by the Board of Bar Overseers said Cape and Islands assistant district attorney Laura Marshard violated professional conduct rules when she met with a witness without the consent of the witness’s lawyer and recommended the suspension.

The board’s decision affirms a finding last fall by a three-member hearing committee. The committee recommended that Ms. Marshard face a public reprimand.

In the decision issued this week the full 12-member board said they agreed with the committee’s factual findings, but recommended a harsher penalty, a one-month suspension with reinstatement contingent on successful completion of a legal ethics class.

“While we agree with the committee’s findings and conclusions, we believe that they warrant the more serious sanction of a suspension,” the memorandum says in part. “We are particularly troubled by the fact that the respondent tried to mislead a judge when she said that the witness did not have appointed counsel at the time she spoke with him, and when she failed to inform the judge that the government had offered not to prosecute the witness if he testified. These were lies.”

Ms. Marshard, a longtime assistant district attorney who lives in West Tisbury, has been under scrutiny since a petition for discipline was filed with the BBO in September 2016. The petition outlined alleged misconduct in three separate criminal cases she handled on the Vineyard in 2013 and 2014.

A hearing before the three-member panel took place last May and June over eight days in May and June, and included testimony from 14 witnesses and hundreds of pages of transcripts and 76 exhibits.

The first claim focused on a 2014 jury trial in Dukes County superior court for an assault case. Bar counsel alleged that Ms. Marshard tried to obstruct justice by improperly raising issues of self-incrimination. Another claim centered on a 2013 drug investigation, when Ms. Marshard allegedly failed to correct a state police sergeant who misrepresented a detail about an arrest before a grand jury.

The BBO said it concurred with the hearing committee that Ms. Marshard did not violate rules in count one and count three.

The board said it also agreed with the finding in another count that Ms. Marshard met with a defendant at the courthouse without his attorney present. In that case, Ms. Marshard allegedly met with a party involved in a 2014 fight without the man’s attorney present.

The full board cited several aggravating factors, including Ms. Marshard’s experience as a prosecutor, a lack of candor before the hearing committee, including “outright falsehoods,” and allegedly misleading a judge.

“Given the multiple misrepresentations to the court, it is appropriate to consider the respondent’s falsehoods in aggravation,” the memorandum says.

In a statement issued Thursday, Ms. Marshard's attorney Elizabeth Mulvey said Ms. Marshard respects the decision.

“ADA Marshard is pleased that the hearing committee found no basis for the other violations charged by bar counsel,” the statement concluded.

“Nevertheless, she recognizes the serious nature of this matter, and respects and accepts the board’s decision.”

On Friday a spokesman for Cape and Islands district attorney Michael O’Keefe said Mr. O’Keefe was in Boston attending district attorney meetings and he would respond after he had a chance to read the report and speak with Ms. Marshard and her attorney.

On Monday the district attorney announced a one-day training session for prosecutors and defense counsel to be held June 14. The seminar will cover conflicts, discovery, witness preparation, and ex parte communication, among other things.

Mr. O’Keefe said in a press release that continuing ethics education is important in a variety of fields. “The recent experience of a member of my staff with the Board of Bar Overseers inspired the idea for this seminar,” he said in the release. Interested parties can register by emailing Cara Winslow at cwinslow@massmail.state.ma.us