Who killed Robin's parents?
Approved answer
The Tragic Loss of the Grayson Family
The youngest member of a family of acrobats known as the Flying Graysons, Grayson witnesses a mafia leader named Tony Zucco murder his parents in an attempt to extort money from the circus that employed them. After this heartbreaking event, Bruce Wayne takes Grayson under his wing as his legal guardian and mentors him to become his sidekick, Robin.