'Stiletto Stabbing' Trial Starts With Accusation of 25 Strikes to Face

March 31, 2014— -- The Texas woman who allegedly stabbed her boyfriend with her stiletto heel at least 25 times was defending herself from yet another instance of abuse at the hands of the man she is accused of murdering, her attorney said at her trial's opening arguments today.

Ana Trujillo, 45, is on trial in the death of her on-again, off-again boyfriend, Dr. Alf Stefan Andersson.

The prosecution today told jurors of the couple's contentious relationship in which Trujillo had a history of being angry with Andersson. Prosecutors have alleged that the Houston woman stabbed her already injured boyfriend to death last year by sitting on him and striking him in the face at least 25 times with her stiletto heel.

Police say Trujillo called 911 shortly before 4 a.m. June 9, 2013. When police arrived at the victim’s luxury high-rise apartment, they say, Trujillo answered the door covered in blood.

Inside, police found Anderson, 59, a medical researcher at the University of Houston, in a hallway, with Trujillo’s stiletto next to him, officials say.

WATCH: Man Killed With Stiletto, Girlfriend Arrested

Andersson. 59, appeared to have about 10 puncture wounds to the head, as well as 15 to 20 wounds along his face, arms and neck, prosecutors say.

Police say the couple got into a fight at a nightclub after another man offered to buy Trujillo a drink. Later, police say, the fight continued at Andersson’s apartment.

Prosecutors allege that Trujillo tried to stop Andersson from breathing by “applying pressure to [his] neck,” according to court documents obtained by ABC News.

Trujillo, a mother of two who’s out on bail, has pleaded not guilty. She was acting in self-defense, her attorney, Jack Carroll, said.

“Stefan Andersson grabbed her, they started wrestling, he got on top of her and she couldn’t breathe,” Carroll said before the trial started. “He got her in a hold.”

Trujillo’s lawyer is hoping to put her on the stand.

“I’m going to have limited time to try to get a jury to understand that although Ana has had problems in the past, she is a kind person at heart,” he said.

ABC News Chief Legal Affairs Anchor Dan Abrams believes the alleged murder weapon – the stiletto heel – is a major factor in the case.

“A stiletto heel is not what’s typically used to kill someone. It’s not a knife or a gun, it’s more of a self-defense tool, something you use because that’s all you have,” Abrams said. “The fact that the weapon was a stiletto heel tends to help the defense.”

Prosecutors will argue that Trujillo also smothered and strangled Anderson, trying to prove to a jury that she went too far, Abrams said.

“This is not an easy case for the prosecution,” Abrams said, “which seems to have already conceded that there was some sort of argument that led up to the killing.”

If convicted, Trujillo could face anywhere from 5 years to life in prison.

The Associated Press contributed to this story.