When Professor Layton, Luke, and Emmy wanted to find out who had purchased the "Specter's Flute" from the black market, they searched the normal market and asked around for information. Marilyn alerted Crow, who dressed up as the Black Raven, and leapt down from the roof above the stall Layton, Luke and Emmy were looking at, dodged Emmy's kick, and was pursued by her to the street corner where he switched places with Badger, who led Emmy on to the rooftops, starting the chase. The Black Ravens switched places with each other to confuse the three, all the while seeming like just one incredibly fast person.
At the end of the chase, Crow confronted them again, inroducing himself as the Black Raven, and welcoming them to his market. He then left them with the clue "put [his] body together" to lead them to the market. He then met them again in the auction hall of the black market, where Layton exposed the Ravens' trick. Crow took off the costume and congratulated Layton, before telling them that the ocarina was bought by Evan Barde a year ago. He also helps Layton later in the game, with the trap for the specter, and the catapult.
He is also the one who orders the black ravens to help Loosha break down the dam, to stop the machines - effectively saving the town.