Floral tributes have been laid at the scenes of Derrick Bird's shootings across Cumbria.
It is believed the carnage began when the 52-year-old taxi driver left his home in the village of Rowrah on Thursday morning.
He first shot dead his twin brother David, at his home at High Trees Farm, Lamplugh.
He then travelled to Frizington, where the family's solicitor was killed on his driveway in Frizington Road.
Kevin Commons, aged 60, worked at KJ Commons solicitors which has offices across the region.
Next, Bird drove seven miles to Whitehaven where he shot dead taxi driver colleague Darren Rewcastle before heading through villages and countryside in west Cumbria, apparently choosing his targets at random.
Retired Sellafield worker Kenneth Fishburn, who was in his 60s, was shot dead in Egremont, while Susan Hughes - who was also in her 60s - was killed while carrying her shopping in the town.
The gunman then moved on to the village of Wilton and murdered retired couple James and Jennifer Jackson, who had been talking to others in the Town End Farm area.
Part-time mole catcher Issac Dixon, aged in his 60s, was the next to be targeted. He was shot and killed at the edge of a field in Carleton while he talked to a local farmer.
Then in Gosforth, Bird shot dead rugby league player Garry Purdham at point blank range as he worked in a field.
There were further shootings in Seascale, where cyclist Michael Pike, 64, and Jane Robinson, who was in her 70s and delivering Betaware catalogues, were both killed.
The twelfth victim is understood to be 23-year-old estate agent Jamie Clark, who was driving through Seascale when Mr Bird opened fire at him.
It was unclear whether he died from gunshot wounds or the resulting crash.
Before Bird was found dead in Boot - shortly after crashing his car near the River Esk - his rampage had spanned about 25 miles.