The man's wife said he mentioned that he "wanted to die" and that he was in pain before he attempted to strangle her, which she said is something he says often.
Her attorney told the court her kids currently believe that their father is "missing" and that their mother has been taken away.
The woman said she met the man Thursday and began dating him Friday before he allegedly admitted to her that he killed his brother Saturday.
A 20-year-old Massachusetts man has been charged with murder, with police accusing him of stabbing his 17-year-old partner with a sword.
