Three of the four males arrested and taken to police stations for questioning have been released without charge, as investigations into last week’s shooting of NSW police employee Curtis Cheng outside Parramatta police headquarters continue. An 18-year-old man, who was arrested from a home in Wentworthville on Wednesday in the anti-terrorism raids carried out by NSW police across Sydney, has been detained for further questioning.

Around 200 armed police forces raided homes in Wentworthville, Marsfield, Merrylands and Guildford at dawn after last week’s terror attack outside NSW police headquarters at Parramatta, which resulted in the death of Cheng.

Even though the 18-year-old has been held in custody, no charges have so far been laid on him. NSW Police Commissioner Andrew Scipione said that though the entire situation was incredibly frustrating, the law has, however, clearly outlined the rules when a suspect can be held in custody.

Scipione told Alan Jones on radio station 2GB that investigators are thoroughly examining the equipment and information seized during the raids on Wednesday.

"Only when we have sufficient evidence that can put us in a position where we can charge an offender with an offence, put them before a court, that we can hold them," he said. "Much happens during the course of arresting them. We've searched properties, we've seized material, we've seized equipment. We do a whole range of things that are very useful in the ongoing investigation, but again, when we've got sufficient evidence or intelligence to get a warrant, we actually execute the warrant and then we're looking to go to the next stage.”

He also said the police have seized a large volume of materials during the searches and it is going to take a substantial amount of time to sift through them. Farhad Jabar, the 15-year-old gunman who was killed after he shot Cheng dead, was radicalised beyond doubt, according to Scipione. However, authorities are certain Jabar was not alone in this crime.

The 16-year-old, among the three youths arrested on Wednesday, was from Wentworthville while the two 22-year-olds were from Merrylands and Marsfield.

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