A former policeman, who killed a grandmother during a 100mph plus "hair-raising joyride", has been jailed for six-and-a-half years.
Malcolm Searles, 24, who had left his police station to deliver an 18th birthday card to his sister, was in a marked patrol car with his blue lights flashing and siren sounding as he repeatedly broke the speed limit.
At one point his on-board computer recorded him doing 104mph in a 40mph limit area while treating his father and uncle to an illegal display of his high-speed driving skills, and at another he was clocked at 107mph in a 70mph zone.
London's Southwark Crown Court heard many of the roads he sped through were "densely populated" housing estates where children were playing football on the pavements and where double sided parking allowed only single file traffic.
Finally, after a "prolonged course of dangerous driving lasting over an hour" and covering a total of 22 miles, he ploughed into 61-year-old pedestrian Sandra "Sandy" Simpson.
Seconds before he had been travelling at 56mph - almost twice the speed limit - when he first saw her, but was still travelling at 56mph when he killed the mother-of-three.
Michael Mulkerris, prosecuting, told the court: "Had he been driving at the legal limit he would have been able to stop."
He said Mrs Simpson, who had taught her children to cross the road near her her home in Bromley, south-east London, died of head and chest injuries despite efforts by paramedics to save her.
Later he tried to lie his way out of trouble, claiming he had been following a speeding car he believed had been stolen.
Searles, from North View, Swanley, Kent, pleaded guilty at an earlier Southwark Crown Court hearing to one count of causing death by dangerous driving, one count of dangerous driving, and two counts of speeding on August 24 last year.