Who killed Robin's parents?
Approved answer
The Tragic Fate of the Graysons
The youngest member of a family of acrobats known as the Flying Graysons, Grayson witnesses the brutal murder of his parents at the hands of mafia boss Tony Zucco. Zucco's motive was to extort money from the circus that employed them. Following this tragic event, Bruce Wayne takes Grayson under his wing as his legal guardian and trains him to become his sidekick, Robin.