The brother is responsible for Romeo and Juliet's marriage and helped Juliet fake her death. Lord Capulet is responsible for forcing Juliet to marry Paris and threatening her if she didn't. Finally, the nurse is responsible for the deaths of Romeo and Juliet, since she encouraged Juliet to marry and waited too long to stop her and convince her to marry Paris. These three characters were responsible for the deaths of Romeo and Juliet, because if one of them had not done their part, Romeo and Juliet could have lived a much happier life.