"Philipp F." had left the religious group some 18 months ago, the head of state security in Hamburg, Thomas Radszuweit, told a press conference on Friday. According to the official, the business consultant parted ways with the religious group "apparently not on good terms."
Prior to Thursday's shooting, police had visited Fusz's apartment in February in response to an anonymous tip claiming he was suffering from an undiagnosed psychiatric illness.
At the time, police found insufficient grounds to confiscate his legally owned semi-automatic pistol, Hamburg police chief Ralf Martin Meyer told reporters.
The unborn child was confirmed by Hamburg Police News Conference on mass shooting to be 7 months old. Again, our sincere condolences to the community in Hamburg, Germany.
At around 9 p.m., the gunman began shooting through a window of the Kingdom Hall of Jehovah's Witnesses during a service that brought together dozens of people.
Fusz shot dead seven people and wounded eight others. Among the dead was an unborn baby whose mother survived the attack with serious injuries, as well as four men and two women.
Police officers arrived minutes after the shooting began. Fusz turned his gun on himself and took his own life. Later Thursday night, police searched the gunman's apartment and found 15 loaded pistol magazines and four other boxes of ammunition.