I think you'll find the BBC is quoting the Australian news media and the police in regards to "known mental health".I am, fwiw, in agreement with @RoyalGreenJacket. Media coverage is showing double standards. The first thing the BBC report mentions is the mental illness. You have to get some way into their report before the seeming Jihad link to the attack is mentioned. It does not stand comparison to the way the BBC shouted out about the mosque attacker being White.
He also had a USB drive with white extremist data on it. Bystanders are confused on whether or not he shouted Allahu Akhabar with some saying he did but didn't seem to be able to pronounce the words properly.
police later said the man also had in his possession a thumbnail USB drive containing information related to white supremacy.
Asked by a reporter whether the conflicting religious references suggested to him a mental health problem at the root of the crime, New South Wales Police Commissioner Michael Fuller said, "certainly all the evidence points to that" at this stage of the investigation.
Of course, some will say only the true martyrs of Islam actually know those words despite the fact the press (and those on here) have mentioned them many (many) times. Perhaps some lost tribe in the Amazon may not have heard the words before but pretty sure most others actually have.
It's a suicide by cop scenario regardless of the Crusaders early morning shouty bit.