describe how the motive for murder is discovered in trifles?

The ladies discover the morive for murder in their small observations, although their husbands never quite catch on. When George Henderson asks casually about the quilt and the empty birdcage. Mrs. Peters says they think the quilt was knotted, and Mrs. Hale says she thinks the cat got the bird and ran away after Wright's death. Henderson reveals that they have found no signs of the murderer, and he and Henry Peters return upstairs. Mrs. Peters admits that when she was a girl, a boy killed her kitten, and she in return had wanted to hurt him, while Mrs. Hale wonders what it was like not to have children. Mrs. Hale suggests that the bird, a canary, would have sung in the manner of the young Mrs. Wright and that John Wright had caused both her and the bird to stop singing, with the implication that Minnie Wright killed her husband in revenge for the canary. The stillness of the house after the bird's death would have been awful, as Mrs. Peters notes. She says that "the law has got to punish crime," but Mrs. Hale recalls Minnie Foster and berates herself for not coming to visit and sympathize. They decide to pretend the fruit preserves had not been destroyed, and Mrs. Peters is glad the men heard nothing about their discussion of the dead canary.