Details emerge about former school principal, brother and sister-in-law accused of killing officers in Australian ambush

Australian police are investigating the extremist views of three people who shot and killed two officers and a neighbor at a rural property before they were killed hours later by police in a gunfight.

Investigators will look at the possible extremist links of the killers after a series of posts under the name of Gareth Train, one of the killers identified in the wake of Monday's deadly shootout, were found on conspiracy theory forums, Queensland Police Commissioner Katarina Carroll said late Tuesday. The posts include references to anti-vaccine sentiments and claims that other high-profile shootings were hoaxes or false-flag operations.

"It's very difficult at the moment for us to reason with what has happened, there are no obvious reasons," Carroll told the Australian Broadcasting Corp. But she added she had no doubt that over the coming days and weeks, police would come back with some insight into the tragic events that unfolded.