The House is set to vote Thursday on whether to remove Dorchester Rep. Carlos Henriquez from office after the House Ethics Committee unanimously recommended his expulsion from the Legislature following his conviction last month on two charges of assault and battery.

The last time a House member was expelled was 98 years ago and the extraordinary step of expelling Henriquez, if approved, would mark just the third expulsion since 1906.

Henriquez, a sophomore lawmaker who is serving six months of his sentence in the Billerica House of Correction, appeared before the Ethics Committee for nearly seven hours on Tuesday as members of the committee deliberated his fate and then filed their report (H 3894). It was the third time Henriquez has been brought to the State House in handcuffs in the past several weeks to defend himself.

“The committee investigation was conducted in a fair and impartial manner and I want to state that right now for the record. There was no preconceived notions by anyone on the committee as to what the outcome of the Ethics Committee hearings would be,” said vice-chairman Rep. David Nangle, a Lowell Democrat.

Nangle said the committee met three times since the matter was referred by House Speaker Robert DeLeo on the afternoon of Henriquez’s conviction on Jan. 15, and reviewed 78 exhibits, 11 police reports and over 1,000 pages of trial transcripts. Henriquez was convicted of assaulting a woman he had been dating during an incident during the summer of 2012.

DeLeo issued a statement shortly after the committee recommended expulsion. “The Representative was convicted of serious charges by a jury and found to have violated the Rules of the House. I will vote to follow the Committee’s recommendation to expel him,” DeLeo said.

Henriquez did not comment to reporters as he left the committee hearing room Tuesday night.

The House plans to take up the report from the Ethics Committee on Thursday when it convenes for a formal session. Henriquez’s attorney Stephanie Soriano-Mills said she did not know if Henriquez might resign before the vote in the House, or if he would avail himself of his right to appear before his House colleagues prior to the vote to address the charges against him. A simple majority vote is required to expel Henriquez.

Henriquez, who is appealing his conviction, told the committee in an opening statement attached to the final report that he was innocent, and called acts of domestic violence “cowardly and shameful” and charges he was embarrassed to be associated with.

“I am not who my accuser seeks to portray me in the media,” he said.

He also tried to argue that the Ethics Committee was biased against him, due in large part to early public calls for his resignation from committee member Rep. Elizabeth Poirier, a Republican from Attleboro.

The Ethics Committee has recommended expelling Henriquez under Rule 16A(1), which states that members shall “make every reasonable effort to avoid transactions, activities, or obligations, which are in substantial conflict with or will substantially impair their independence of judgment.”

Soriano-Mills accused the Ethics Committee of bending the House rules to fit the circumstance on Henriquez’s case.

“They didn’t draft any rules that talk about a legislator’s action being unbecoming. They didn’t. Now they want to almost fit a square peg into a round hole,” she told reporters.

Soriano-Mills also said that Henriquez has been in daily contact since his incarceration with his State House staff to continue his work on behalf of his constituents, and had been voting and making good decisions for his district since the charges were first filed 18 months ago.

“The conviction on two misdemeanor assault and batteries and the media frenzy that happened now caused the House to act upon a rule that doesn’t apply. It essentially deals with the independence of thought being affected, or his independence of judgment. That same judgment has been around for 18 months. He has been making all kinds of great judgments,” she said.

Members of the Ethics Committee dismissed the criticism, stating that they had no difficulty applying the existing House rules to Henriquez’s case.

“The specific rule he violated was Rule 16A(1), which clearly states that a member cannot engage in activities that will substantially impair their independence of judgment,” said state Rep. Garrett Bradley, a Hingham Democrat and attorney. “Clearly his conviction and incarceration have done that since he cannot come to the State House and vote, cannot handle matters within his district, and has severely compromised his ability to be a representative.”

House Speaker Pro Tempore Patricia Haddad, who also sits on the Ethics Committee, said the committee had little choice but to recommend expelling Henriquez given his conviction and the facts of the case.

“As we take the oath of office every two years we say we will uphold the Constitution. We say we will follow the laws of Massachusetts. And in a case where one of our own has been found guilty in a court of law, the inference is that is conduct unbecoming. That is conduct we can’t abide in our chamber,” Haddad said.

The Somerset Democrat also suggested that the House’s plans to take up domestic violence legislation before the end of the session in July would be clouded if Henriquez was not removed from office.

“If we as a House later in the session plan to take up the domestic violence issues, we can’t as a body not sit in judgment of one of our own just as harshly as we would sit in judgment of an average person, and more so because we have that ability to promulgate laws that will ultimately defend women,” Haddad said. “While that should not be the overriding issues here, it has come into play and is something we should consider.”

Henriquez asserted his innocence to the committee, but Bradley said there were questions asked by the committee that he refused to answer that “would have gotten to the heart of the matter of what happened that night with the young woman who was assaulted.”

No other witnesses were called, though the committee did review the sworn testimony provided at trial. Bradley also said the testimony of the victim that she was struck repeatedly during the incident was substantiated by photographic evidence reviewed by committee.