Why did moose flanagan move to alcatraz?

Moose Flanagan moved to Alcatraz because his family relocated there due to his father's job as a prison guard. The move was also motivated by the need for a new start, as Moose's family sought a fresh beginning away from their previous life in San Francisco. Additionally, Moose's sister, Natalie, who has special needs, required a more supportive environment, and Alcatraz offered the stability their family needed.