A judge has begun hearing arguments in the fourth trial of a 54-year-old upstate New York man accused of killing his estranged wife in 2001.

Calvin Harris's request for a non-jury trial was granted Monday just as jury selection was set to start. Judge Richard Mott began hearing arguments in Harris's murder trial Thursday and the prosecution has called its first witness, the couple's baby sitter.

Prosecutors say Harris killed his 35-year-old wife late on the night of Sept. 11, 2001, in the Spencer, New York, home they still shared with their four young children. Defense lawyers claim authorities overlooked two other likely murder suspects.

Two previous convictions against Harris have been overturned. His third trial last year ended in a hung jury.

Michele Harris's body has never been found.