PORTLAND – The suspect in the Labor Day weekend killing spree near the Sunday River ski resort in western Maine was placed on a suicide watch Tuesday after being treated for self-inflicted wounds, officials said.

Cumberland County Sheriff Mark Dion said 30 sutures were required to close the wounds on Christian Nielsen’s scalp. Nielsen used a disposable razor Tuesday morning to make the cuts that resembled the letter “X,” Dion said.

The cook is charged with killing three women and dismembering their bodies at the Black Bear Bed & Breakfast in Newry. He also is charged with killing an Arkansas man and dumping his body in the woods in the neighboring town of Upton.

The state Attorney General’s Office and Maine State Police are reviewing the facts that led to the latest jail incident. The Sheriff’s Department will lead a separate investigation for any potential violations of internal policies and procedures.

Nielsen, who is being held without bail on four counts of murder, was moved to Cumberland County Jail after he allegedly attacked an inmate at Oxford County Jail days after his arrest. His trial is tentatively scheduled to get under way in October 2007.

Authorities say the killings began on Sept. 1 when Nielsen killed a fellow Black Bear tenant, James Whitehurst, 50, of Batesville, Ark., and burned and disposed of his body in the woods in neighboring Upton.

Two days later, he allegedly killed the inn’s owner, Julie Bullard, 65. The next day, Labor Day, he allegedly killed Bullard’s daughter, Selby, 30, and her friend, Cindy Beatson, 43, when they arrived unexpectedly at the inn.