an occasion when something bad happens to a person who seems to deserve it, usually because of bad things that person has done

What poetic justice it is that Brady has to go to court to plead to be allowed to die, just like his innocent victims pleaded to be allowed to live. 布雷迪不得不上法院恳求被处死，就如同当初无辜的受害者恳求免于一死一样，真是报应。