Police officers who frantically chased crazed killer Derrick Bird were forced to abandon their pursuit when he turned his gun on them.
Three unarmed officers followed father-of-two Bird but could not stop the massacre.
Cumbria Police insisted there was never an opportunity to stop the carnage - which left 12 dead.
A neighbourhood policing officer first gave chase after hearing shots in Whitehaven and commandeering a car. But as the officer raced towards Bird's car the 52-year-old pointed his gun out of the driver's window and fired at a passing taxi. The pursuit was abandoned to help the taxi driver and his female passenger who had been shot. Two other officers in a police van then took up the chase but stopped when Bird pulled up and pointed his gun at them.
A motorist has also told how he risked his own life chasing Bird. Grandfather Paul Goodwin, 48, chased the lone gunman as he sped around Whitehaven town centre. Describing last Wednesday's horror, Mr Goodwin said: "Am I brave? No. Stupid, yes. My mum said I could have been killed. I just didn't think, it was instinctive."
Mr Goodwin continued: "I followed as he turned right on to Scotch Street. I thought he was heading out of town but instead he turned right on to Lowther Street and went round the one-way system back on to Duke Street. At this point I can see lots of people and I start waving my hands shouting, 'That's him in the taxi and he's got a gun'.
"At that point I hear two more bangs into the taxi rank and I can see the gun. He carries on up Duke Street and as he turns on to Duke Street I can see the police running from the police station nearby. I recognised the copper as Pc Mick Taylor, who I know, and I shouted at him, 'Get in'."
Mr Goodwin said Bird then pulled up in Scotch Street and called over to taxi driver Paul Wilson who was walking to the police station and as he approached his car shot him in the face. "I said to Mick that this guy has got something against taxi drivers," Mr Goodwin said. "We followed him on to Coach Road and we are about 10-15 yards behind." Mr Goodwin then explained how he saw Bird shoot another taxi driver, who he later found out to be Terry Kennedy.
Bird's killing spree began in the early hours of Wednesday when he murdered his twin brother David. It is believed this - and the killings of family solicitor Kevin Commons, 60, and fellow cabbie Darren Rewcastle - were sparked by bitter grudges.
Meanwhile, hundreds of people have packed a church to pay their respects to those killed in the shootings. The service at St Begh's Priory in Whitehaven was led by Rt Rev Michael Campbell, Bishop of Lancaster, who told the 500-strong congregation that the thoughts and prayers of the Catholic community were with those who were suffering. During his sermon, the Bishop said: "Let us pray for the people of West Cumbria and we will wipe away every tear of their lives."