Mrs. Minnie Wright is the unseen main character in Susan Glaspell's "Trifles", which deals with the story of a woman who seems to have lost control of her emotions and snaps, killing her abusive husband.
Her motive for murder goes far beyond the killing of her bird. The canary is also more than just a symbol. Minnie is known for her radical change after she gets married to her husband, John. During her youth, she is apparently a woman who is full of life and who loves singing and dancing. Once she marries John, she seems to disappear even from the people who know her well. Later, she begins to show signs of self-deprecation: She does not wear nice clothes anymore, does not take care of hear appearance as much as she usually does, and she becomes isolated from everybody.
Long after this isolation, John shows up dead and she is the primary suspect, being that she is on location when it all takes place. However, it is through the "trifles"-those little things that do not seem to mean much- that are found by Mrs. Hale and Mrs. Peters, that we come to realize that Mrs.Wright was under a horrid amount of trauma.
The trifles include Mrs. Wright's disparate stitching. This is abnormal because the women in the story speak of stitching as an activity for leisure. Therefore, we can argue that, between the isolation, the trauma and the loneliness, Minnie's canary could be the only living thing that she could connect to...and her husband kills it, making her snap completely.
Mrs. Wright killed her husband because he killed the canary which represented her. The canary was a symbol of what Mrs. Wright used to be a singer.