AUGUSTA – A mental health exam for Christian C. Nielsen, accused of killing four people over Labor Day weekend, has been postponed.

The exam, originally scheduled for last Friday and last Tuesday, will be held on Dec. 12 and Dec. 13.

According to a letter filed with Oxford County Superior Court by Dr. Ann LeBlanc, director of the State Forensic Service, the date was postponed because the defense had requested more time to review discovery materials prior to the examination.

In the meantime, officials involved will review materials relating to the crimes.

Defense attorney Ron Hoffman did not respond to a written request for comment.

Reached by phone Monday, William Stokes, chief of the Maine Attorney General’s Office criminal division, said he was unaware of the change, but it is not uncommon in such cases.

The mental examination was requested in a motion by the state, which was granted by Oxford County Superior Court Justice Robert E. Crowley Oct. 18. Stokes said previously that the defense might use an insanity plea, so the state needed to be prepared.

“The defendant’s state of mind at the time of the offenses is likely to be a critical issue at the time of the trial,” Assistant Attorney General Andrew Benson wrote in his memorandum supporting the motion.

The defense objected, stating that if examined, Nielsen may incriminate himself, and it would also deny him due process.

Defense attorneys Hoffman and Margot Joly have hired a psychologist to do their own evaluation of Nielsen, however, it could not be carried out because they did not have all the details of the state’s investigation.

Nielsen has been indicted on charges of killing James Whitehurst, 50, of Batesville, Ark., a guest of the Black Bear Bed and Breakfast in Newry; Julie Bullard, 65, owner of the inn; Selby Bullard, 30, of Bethel, Julie’s daughter; and Cynthia Beatson, 43, of Bethel, Selby’s friend.

Nielsen later told his father that he had committed the crimes, and his father called the police. The case is expected to go to trial next fall.

According to the search warrant released by state police, Nielsen told Whitehurst he was taking him fishing in Upton. There he killed him, burned and buried his body, police said.

Nielsen had told police that he killed Julie Bullard in her bedroom at the inn because she might question where Whitehurst was. According to the warrant, he also shot her dogs because they looked unhappy.

Selby Bullard and Beatson showed up at the inn unexpectedly, Nielsen told police, and he realized he had to kill them, too.