Grayle was a powerful crime boss, and a collector of unusual or unique artefacts, such as ancient Chinese vases and pottery. His home, located at 406 94th Street in Manhattan, held a myriad of antiques and otherwise intriguing specimens. By 1938, Grayle had acquired several baby Weeping Angels, which he kept locked away in his cellar, and an adult Angel he obtained after Max Kliener's death kept chained in his office. He had the latter tortured to see if it could feel pain.
Grayle hired private investigator Sam Garner, ostensibly to look into the claims of Weeping Angels at Winter Quay. Garner was captured there by the Angels, who fed off of his time energy by sending him backwards to live out his life in a room at Winter Quay.
In order to gather more information on the Angels, Grayle had River Song captured and tightly held in the grasp of his captive adult Angel, which resulted in her breaking her wrist to escape. He also had Rory Williams thrown into the cellar, where he was set upon by the young Angels and as a result, was sent to Winter Quay.
When the Doctor's TARDIS arrived nearby, the time distortion energy released from the unstable landing caused Grayle to collapse from shock, and his defenceless mansion was invaded by a duo of Angels. (TV: The Angels Take Manhattan)