The Lowell Sun reports that a judge Thursday continued to hold Benjamin DiChristina without bail after a not guilty plea was entered.
Prosecutors say DiChristina choked and cut his 28-year-old girlfriend before attacking his parents on Oct. 4 in the family's Acton home.
DiChristina's father, 57-year-old John DiChristina, died days after the attack.
Benjamin DiChristina was originally charged with armed assault with intent to murder, but that was upgraded to murder after his father's death.
Prosecutors say DiChristina's parents had sought mental health treatment for their son but he was assessed and released from a hospital before the attack.
His attorney says he has a history of mental health issues.
Information from: The (Lowell, Mass.) Sun, http://www.lowellsun.com
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