RCMP say gunman behind mass killing in Nova Scotia was 'injustice collector'

Nova Scotia RCMP say the gunman who killed 22 people in one of Canada's worst mass murders was an "injustice collector" whose personal grudges boiled over in rage.

RCMP Supt. Darren Campbell told a briefing today that a behavioural analysis of the gunman has found some victims of his violence were targeted for perceived past injustices while others were selected at random.

Campbell said forensic psychologists have developed the term "injustice collector" to describe someone who "may have felt slighted or cheated or disrespected at any point in time in their lives. It may be real, it may be perceived by the individual, however as a result, these injustices were held onto."

The RCMP briefing, the first in more than a month, also disclosed that the police officer killed on April 19 exchanged gunfire with the killer, Gabriel Wortman, after colliding with the replica police vehicle he was driving.

"We can also tell you that the gunman's vehicle sustained more damage than Const. Stevenson's police vehicle, that she bravely engaged the gunman," Campbell said.

He said it was the gunman who rammed into Const. Heidi Stevenson's vehicle, and he noted she was wearing soft and hard body armour.

Police say they have confirmed that three of the five firearms in the gunman's possession had been obtained illegally in the United States, one was obtained illegally in Canada and the fifth was taken from Stevenson.

Campbell said that in contrast to what police had earlier said, the gunman did not use the replica police vehicle to pull over any victims who were in their vehicles.

Investigators have yet to reveal key details about the shooting rampage, which started late on April 18 in Portapique, N.S., and continued for the next 13 hours across northern and central Nova Scotia.

Gun control advocates say details about the firearms used are important to the discussion surrounding the federal government's move to ban 1,500 military-style assault firearms.

A Mountie fatally shot the 51-year-old gunman at a gas station in Enfield, N.S., about 90 kilometres south of Portapique on the morning of April 19.

In addition to Stevenson, his victims included two nurses, two correctio