The eldest son of notorious mobster Fat Tony, A.J. was slated to succeed his father as Boss of the De Santa crime family, but he wanted nothing to do with the criminal life and began studying to become an Auror. After graduating from Cascadia, Anthony began Auror training, graduating in the summer of 1999. Anthony was such a great Auror that he was asked for by the President of MACUSA to be on his personal security detail. In 2002, the Russian Minister for Magic was under threat of a coup by radicals. A.J. was sent to Russia and was the personal bodyguard of Minister Romanov's daughter, Anastasiya. During that time, he foiled an assassination attempt on Minister Romanov and his daughter, which earned him the Order of Peter the Great.
After his stint as Anastasiya Romanova's personal bodyguard, Anthony continued his work as an Auror back in America, but returned to Russia to pursue a relationship with the Minister's daughter. The pair married in 2008 after several years of courtship an had two children; fraternal twins Niko Roman and Natalia Elena De Santa were born in 2010. A.J. moved to Russia permanently and was given a home in the south of the country, where he and his family still live as of 2017.