Two victims, Melvin Cravitz, 66, and Adrian Daulby, 53, were shot by armed police while sheltering inside the synagogue, with Daulby tragically losing his life from a stray bullet.
The Independent Office for Police Conduct (IOPC) has initiated an investigation into the fatal police shooting.
Al-Shamie, who was not carrying a firearm, was on bail for an alleged rape at the time of the attack, and his family has condemned his actions.
Three other individuals have been arrested on suspicion of planning a terror attack in connection with the incident.