John Grayson is a supporting character in DC the Batman franchise. He is the husband of Mary Grayson and the biological father of Melinda Zucco and Dick Grayson, who was adopted by Bruce Wayne and became known as the vigilante Robin, then Nightwing. Their trapeze was sabotaged by Tony Zucco in revenge against Haly's circus for refusing to pay protection money for them, leading them to fall to their deaths in front of a crowd and their eight-year-old son.
It is recently revealed that it was personal and Zucco sabotaged the Graysons' trapeze out of revenge against John for fathering a child with his ex-wife.