NSW Police and emergency services were called to Hill Street, Strathfield South, about 11:00am on Saturday, February 27 following reports of a suspicious car on the street.
Police said they searched the car and found two rifles and an improvised explosive device.
Court papers said Mangolini had been charged with possessing a .22 caliber Kostok bolt action small arm rifle and a 7.62 caliber SKS bolt action rifle, and that he did not have permits for either weapon.
He was also charged with possessing a homemade explosive device which contained gun powder, shot pellets and an ignition wick.
Hill Street is a short street that includes a number of houses and the Australian International Academy, an Islamic school.
With the help of Rescue and Bomb Disposal Unit officers, the police safely dismantled the device and items were seized for forensic examination.
Police checks on the car later revealed it had been stolen from Chullora.
The Joint Counter Terrorism Team arrested Mangolini yesterday.
Court papers also show that in an unrelated matter, Mangolini faced Burwood Court yesterday on stalking and intimidation charges relating to a woman who is his ex-partner and the mother of his three children.