RCMP in Nova Scotia were in the process of preparing an emergency alert when the gunman was shot dead in Enfield near Halifax International Airport.

Police gave an update today on the timelines and other aspects of the shooting rampage that left at least 22 victims dead. They are searching 16 crime scenes, including five burned-out houses, across several communities over 50-kilometres. No additional victims have yet been found.

They say their response was fluid and dynamic beginning with the first call to 911 Saturday night at about 10:30 from Portapique. They also say the gunman acted alone.

They have established a special tip line for anyone with information about the incidents or the time leading up to them.

The number is 902-720-5959.