The boy was rushed to the hospital, where he later died. His victim, whom he did not know, is said to be in a serious but stable condition.
Police have uncovered evidence that the young man may have been radicalized online.
“It appears at this point that he acted individually and on his own terms,” Western Australian Premier Roger Cook said.
Police in Western Australia said they received a call late on Saturday night from a teenager who warned them he was planning to commit a “violent act”.
Police Commissioner Branch told a news conference that a call came in a few minutes later about “a man with a knife running around a car park” in Willeton, a southern suburb of Perth.
Three police officers arrived at the scene and found the 16-year-old armed with a long kitchen knife.
The first two officers used a taser, but as the teenager continued to approach, a third officer fired a shot that killed the 16-year-old, the commissioner said.
The teenager allegedly had “difficult problems” and was involved in an anti-radicalization program for several years, which aimed to fight against extremist ideologies.
