Orion Krause right, stands with his attorney Edward Wayland at Krause's arraignment in Ayer District Court in Ayer, Mass., Monday, Sept. 11, 2017. Credit: Josh Reynolds | AP

ROCKLAND, Maine — The Rockport man accused of killing his mother, his grandparents and their home health aide in Massachusetts two years ago is expected to face trial in May pending a final mental health evaluation.

Orion Krause, 24, faces four counts of murder for the Sept. 8, 2017, killings and has been in custody since his arrest. He’s been awaiting a mental health evaluation from the state since his initial trial date was postponed in March when he pleaded not guilty by reason of insanity.

At a status conference in Middlesex County Superior Court last month in Massachusetts, the judge “wasn’t happy that the case was getting old with no clear end on the calendar,” Krause’s attorney Edward Wayland said in an email. A May 18 trial date was set.

Wayland said that the state’s mental health expert has yet to meet with Krause. However, prosecutors told Wayland the evaluation will likely be completed before the next status conference on Jan. 21, 2020.

Krause is accused of using a baseball bat to beat his mother, Elizabeth “Buffy” Krause, 60; her parents, Elizabeth “Esu” Lackey, 85, and Frank Danby “Dan” Lackey III, 89; as well as their home health aide, Bertha Mae Parker, 68, to death at the Lackeys’ house in Groton, Massachusetts.

Police found the bodies of Krause’s mother and grandparents sitting in chairs in the kitchen. Parker’s body was found in a flower bed, according to police reports. Krause allegedly told investigators he “freed them.”

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

In October 2017, Krause was found competent to stand trial. But a mental health expert hired by the defense who examined Krause prior to trial found that the cause of the homicides was mental illness.

Once Krause pleaded not guilty by reason of insanity, the initial April 2019 trial date was postponed until the prosecution could find an expert and conduct its own evaluation of the case, including Krause himself, and make an independent determination about whether mental illness caused the crime.

If the state’s expert determines that the murders were the result of mental illness, Krause will be found not guilty by reason of insanity and committed to a mental institution. However, if the state’s expert finds that mental illness was not the cause, the case will go to trial in May and both the defense’s expert and the state’s expert will testify on their findings.

If convicted on all four charges, Krause faces a maximum of four life sentences without the possibility of parole.