Police have shot dead a man who came at them with knives, after the attacker went on a two-hour fatal stabbing spree.
The 34-year-old Roxburgh Park man was killed at Kew shortly after midnight on Thursday after he had already slashed a protective services officer in the face and then killed a 30-year-old woman and a 59-year-old man in three separate attacks.
The man had scant criminal history before the overnight rampage and was not a person of interest to the counter-terrorism command, Chief Commissioner Graham Ashton told reporters on Thursday.
"We are short of motivation at this time as to why he has done what he has done," Mr Ashton told reporters.
Police say the random acts of violence started about 10.40pm on Wednesday.
A protective services officer at Jolimont train station was left with non life-threatening cuts to his face when he was approached by a stranger who attacked him with a large kitchen knife.
The attacker then got on a train and soon after, two women were found in a car at Hawthorn with life-threatening stab wounds.
A 30-year old woman died and the other, aged 31, is at The Alfred Hospital fighting for life.
Police were then called to reports of a man stabbed at Kew about 12.15am on Thursday.
The victim, a 59-year-old man, died.
Police found a second man near the crime scene and tried to arrest him.
But the man drew knives and three officers fired their guns.
Large kitchen knives and a switch blade were found near the man after the shooting.
"They were in very close contact with him at that stage," Mr Ashton said.
Roads closed at Kew and Jolimont Station have since reopened after being closed for most of Thursday morning.
Police are not searching for anyone else and the community is not at risk.
