Orion Krause right, stands with his attorney Edward Wayland at Krause's arraignment in Ayer District Court in Ayer, Mass., Monday, Sept. 11, 2017. Krause, of Rockport, Maine, was ordered held without bail at Bridgewater State Hospital pending a competency hearing at his arraignment on murder charges Monday in Ayer. (Josh Reynolds/The Boston Globe via AP, Pool) Credit: Josh Reynolds | AP

A Rockport man charged with killing his mother, grandparents and their home health aide in Massachusetts last fall pleaded not guilty Wednesday, according to news reports.

Orion Krause, 23, faces four murder charges stemming from the Sept. 8, 2017, killings that took place at his grandparents’ home in Groton, Massachusetts.

Krause is accused of killing his mother, Elizabeth “Buffy” Krause, 60; her parents Elizabeth “Esu” Lackey, 85, and Frank Danby “Dan” Lackey III, 89; and their home health aide, Bertha Mae Parker, 68.

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As the charges were read to Krause on Tuesday,he showed no emotion while pleading not guilty to the killings of his grandparents and Parker, the Globe reported. But when his mother’s name was read as one of the murder victims he “trembled visibly,” according to the Globe.

Krause’s attorney, Edward Wayland, told the Bangor Daily News in an email Wednesday that he expects the evidence to show that “mental illness is the entire explanation for this tragedy.” However, Wayland said it is early to say that they will pursue an insanity defense, though he is not ruling it out as an option.

“I believe once the evidence is all in it will be clear that an acute mental illness, and that alone, was the cause of these deaths,” Wayland said.

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Krause was deemed competent to stand trial in October and has been held at Bridgewater State Hospital since his arrest.

Krause allegedly admitted that he committed the killings with a baseball bat, according to police reports.

The bodies of his mother and grandparents were found sitting in chairs in the kitchen, while Parker’s body was found in a flower bed outside.

Krause allegedly told investigators that he “freed them.” When asked where the killings occurred, Krause allegedly pointed toward the woods, according to police reports.

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On the night of the killings, Krause allegedly called a former college professor and said, “I have to kill my mom.”

Krause was ordered to be held without bail, the Globe reported. If convicted on all charges, Krause faces a maximum of four life sentences without the possibility of parole.

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