June 30, 2017 04:45 PM

On Wednesday, jurors in Brattleboro, Vermont, convicted a 64-year-old woman in the 2014 shooting deaths of her 60-year-old boyfriend and his 28-year-old son, agreeing the killings constituted an act of premeditated revenge fueled by the dissolution of her engagement.

PEOPLE learns that Robin O’Neill could be sentenced to life without parole next month for murdering her ex, Steven Lott, and his son, Jamis Lott, the evening of Nov. 18, 2014.

Under state law, O’Neill is entitled to an automatic appeal of her conviction.

Windham County State’s Attorney Tracy Shriver tells PEOPLE the guilty verdict was the result of “a tremendous amount of work by the Vermont State Police and this office.” Jurors deliberated for 9 hours, Shriver says.

At trial, Shriver argued that O’Neill was driven to kill after Lott informed her he was breaking off their engagement.

Shriver tells PEOPLE he told her the wedding was off the weekend before the killings and the last time on the day she fatally shot him, striking him with 12 bullets.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Using three handguns, O’Neill shot Jamis three times in the head before turning her attention to Steven, who was shot seven times in the head, once in the chest, and four times in the groin.

“She was angry, and one of the things I argued to the jury was that it was a remarkable coincidence that on the day her fiancé died, she reported to four people he had hit her,” Shriver tells PEOPLE. “That same night, she called a friend and said, ‘I need you to take care of my dog.’ The friend asked why, and she says, ‘Because I just shot Steve and Jamis.'”

O’Neill’s attorney, Ian Carleton, could not be reached for comment.

But during the trial, Carleton argued that investigators ignored crucial evidence and that they pursued O’Neill single-mindedly, and that ultimately, the state’s evidence did not support a conviction.

Shriver disagreed, telling jurors O’Neill’s DNA was recovered from the guns used to kill the Lotts, and that she had both motive and opportunity.

You May Like