SPRINGFIELD – A lawyer for Jesus Gilberto Garcia, accused of brutally murdering his ex-girlfriend's mother, on Thursday peppered prosecution witnesses about the gory video game marathons the defendant and his friends often engaged in.

Garcia is standing trial in Hampden Superior Court for the savage slaying of Valerie Girouard and a knife attack on Girouard's live-in boyfriend, Kurt Haarman, on July 30, 2010. The couple lived in Hampden with Girouard's two daughters. Her eldest, Mariah Girouard, 15, dated Garcia for more than a year, according to witnesses.

The teens had a tumultuous relationship until the girl broke up with Garcia after he entered the house a week earlier wearing a mask and threatening Mariah Girouard with a knife to show her “the world wasn’t a safe place,” according to testimony.

Mariah Girouard on Wednesday spent two hours on the witness stand telling jurors of their relationship, and the attacks on her mother and Haarman that she witnessed before escaping into the night. She told jurors she was awoken by Haarman’s screams and bolted into the kitchen, where she saw Garcia wearing a ski mask and no pants or underwear, savagely jabbing at the adults with a knife before he sliced her mother’s throat.

Haarman survived the attack and is expected to testify on Friday.

On cross-examination, defense lawyer Paul Rudoff asked Mariah Girouard about the hours Garcia spent playing blood sport video games at both their homes, and revived the theme with witnesses on Thursday.

"They’re pretty gory right? It involves knives and swords," defense lawyer Paul Rudoff asked Antonio Cintron, one of Garcia's nephews. "Sometimes you guys would stay up all night long playing these games wouldn't you?"

Cintron was among a handful of family members at their Fountain Street home in Springfield who were hanging out in their “chill spot” in the basement, drinking and smoking pot, he said. Cintron testified Garcia left in the middle of the night on his bicycle on the night of the murder and returned two or three hours later.

The defense suggested in their opening statements that Garcia’s judgment was tainted during the attacks by the hours of violence the boys immersed themselves in through incessant video game-playing.

It is not the first time a lawyer has raised a video game violence defense. Lawyers for Devin Moore, an 18-year-old Florida resident, attempted to argue it was his love of “Grand Theft Auto” to steal a car and kill two police officers and a 911 dispatcher in 2003.

A judge barred the video game evidence at trial; Moore was convicted in 2005 and faces lethal injection.