A MAN who carjacked a Good Samaritan who had stopped to help him has been jailed for five-and-a-half years. Having just ploughed his own car into a ditch, callous Mark Allgood, 31, chased after the kind-hearted woman, assaulted her, stole her car keys and drove off. The grey Audi A3 belonging to the married teacher was found dumped in Needingworth a few hours later, having been burnt out by Allgood. The terrifying incident took place on the A141 in Huntingdon, at the roundabout joining roads from Wyton, March and Abbots Ripton. Wisbech man Allgood listened with his head bowed as Peterborough Crown Court heard details of the offence, which took place at 8pm on March 4. Craig McDougall, prosecuting, told the court how the woman, in her 20s, had been deeply affected by the carjacking. She watched in horror as Allgood smashed his silver Vauxhall Vectra into a ditch and she then pulled up nearby to phone the emergency services, Mr McDougall said.