A 73-year-old woman accused of killing her 84-year-old neighbor with a hammer went on trial for homicide Monday after a judge refused to accept her guilty plea.

Kathy MacClellan, a gaunt-looking woman with a shock of white hair, was charged with attacking Marguerite "Tuddy" Eyer with the claw end of a hammer on Feb. 7, 2005, in Hickory Hills, a mobile home community north of Bethlehem that is popular with retirees.

Eyer died 13 minutes after being rushed to the emergency room; the coroner said she had been struck in the head 37 times.

MacClellan had been scheduled to plead guilty Monday to third-degree murder in exchange for a sentence of 17 to 39 years in prison. But when MacClellan was asked to agree to the facts of the case as laid out by Northampton County District Attorney John Morganelli, she refused, leading Judge Emil Giordano to order a trial.

MacClellan had earlier waived her right to a jury trial when prosecutors dropped their plan to seek the death penalty. She would have been one of the oldest defendants in modern times to stand trial on a capital murder charge.

Police investigators testified Monday they found Eyer's wallet, checkbook and other items in MacClellan's house and that MacClellan's face, hair and clothing were covered in Eyer's blood.

James Bicking, a neighbor who went to check on Eyer after she pushed her medical alert button, testified that he saw MacClellan coming out of Eyer's house, covered in blood. He went inside and found Eyer lying in a pool of blood. He said Eyer told him, "Kathy hit me with a hammer."

Another neighbor, Dale Hartzell, got to Eyer's house a few minutes later. He said MacClellan told him, "I didn't do nothing." Hartzell said he replied, "You're not going anywhere until the police come," and she sank into a fetal position in the driveway.

MacClellan allegedly told police that she went to Eyer's house with cookies and a photo album and found her on the floor in a pool of blood. She said she laid on top of Eyer because she thought that would comfort her, and got Eyer's blood on her, according to police testimony.