The trial of a Marco Island lady accused of killing her boyfriend continued Friday with opening statements and testimony from state witnesses who described their encounter with the lady and the bloody bed room they discovered on the scene.

Lisa Troemner, 27, faces a cost of second-diploma homicide. Prosecutors say she fatally stabbed her stay-in boyfriend, Trevor Smith, 30, of their house on Park Avenue throughout an argument Dec. 2, 2014.

If convicted, she might resist life in jail.

Six jurors and three alternates have been chosen Thursday after three days of jury choice.

The state and protection introduced their opening arguments Friday morning.

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On the night of Dec. 1, 2014, Troemner crawled into bed, next to a sleeping Smith, with an 8-inch chef’s knife, said Assistant State Attorney Katherine Rumley. Troemner put the knife on a bedside table, Rumley said. 

When the couple woke later that night and began arguing, Troemner took the knife and stabbed Smith in the neck, severing his carotid artery and puncturing his lung, Rumley said.

Trevor Smith. (Photo: Courtesy of Trevor Smith Memorial Foundation)

She stabbed Smith two more times that night, Rumley said.

“His death was almost immediate,” she said. “He just had the strength to crawl along the floor to the end of the bed where he died.”

Rumley said Troemner killed Smith “despite the fact that he was unarmed and in her own words, ‘he would not have hurt her.’ ”

The relationship between Troemner and Smith was only about six months old during the time of the killing and had been a “rocky” one, Rumley told jurors.

The couple had been arguing “almost continuously” the weekend of Smith’s death, she said.

The impetus for the ongoing argument, Rumley said, was Smith staying out “too late” at a friend’s house.

Troemner was upset by that, Rumley said, and went out herself, going to a bar and cheating on Smith.

When Smith found out, she said, he was upset and the two began arguing.

The insults and verbal threatening eventually pushed Troemner “over the edge” and caused her to stab Smith, Rumley said.

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All the blood at the scene was Smith’s and Troemner had no injuries but a self-inflicted wound, prosecutors said.

“The defendant stabbed the victim because she was mad,” Rumley said. “She was mad because he called her names. He wouldn’t stop talking about how she had cheated on him.”

However, Troemner’s defense attorney, Donald Day, painted a different picture of the events that night.

Day said his client was in “stone-cold fear” of Smith and had been verbally and physically abused for…