Sydney attacker advertised himself as male escort and tried to join gun groups

Joel Cauchi had been known to police, particularly over the last five years, but had not been arrested or charged before he committed the attack

Emergency officers outside Westfield Shopping Centre in Sydney (Rick Rycroft/PA)

The Sydney knife attacker who killed six people at an Australian shopping centre advertised himself online as a male escort and tried to join groups of gun owners.

Joel Cauchi, 40, from Queensland, had been known to police, particularly over the last five years, but had not been arrested or charged before he committed the attack on Saturday afternoon.