Lars Thorwald didn’t get along with his wife as they had
constantly argued with each other. This causes him to finally snap and kill
her. His wife, he was having an affair with another woman, who would eventually
aid him in his plan to get away with her murder-as she posed as his wife when
they went out together.
After he kills his wife, he cuts off her body parts and buries them in
various places. He buries her ring in the back yard, and it was nearly dug up
by a dog that belonged to one of his neighbours. Firstly he simply has the dog
leave, but later decides to kill it out of the risk of it finding her ring.
Thorwald met his end when the film’s protagonist, a handicapped man named
L.B. “Jeff” Jeffries, hears his wife scream when killed her and
begins spying on him through his telescope, finally becoming distrustful of the
man. When Jeff is finally able to uncover Thorwald, the man realizes it’s Jeff
who is on to him. He then comes up to Jeff’s apartment and tries to kill him by
throwing him out his window. However, he survives his fall and Thorwald is
arrested once the police arrive.