A man has been convicted of shooting dead a pregnant neighbour after a doorstep row.Thomas Hughes, described in court as a 'wannabe gangster' was found guilty of murdering Krystal Hart, 22, on Good Friday last year.There were cheers from the public gallery as the verdict was delivered by an Old Bailey jury after three hours of deliberations.Hughes, 41, of Stonells Road, Battersea, south London, had denied the shooting, saying another man was responsible.But parts of the incident - including the sound of two shots and Hughes hurrying away - were caught on CCTV.Miss Hart died instantly after being shot through the head. A second bullet was fired into her temple after she crumpled into her doorway.The prosecution said Miss Hart was executed by the petty criminal and drug dealer in revenge for her boyfriend, David Siveter, writing down his car registration earlier that day.Miss Hart was two months pregnant and had recently given up her job as a temporary secretary working in the office of then deputy prime minister John Prescott at the Houses of Parliament.Miss Hart had lived in the upstairs housing association flat in Belleville Road, Battersea, for a year.But a few months after moving in with her mother Debbie Penfold, she fell foul of her downstairs "neighbour from hell" Angie Brewer, 53.The two women had an ongoing county court action and the CCTV was installed to provide evidence.Miss Brewer was blamed for causing most of the trouble and was due to be made the subject of an Asbo. The serial complainer to the authorities, was friendly with Hughes, a loner who lived nearby in a dilapidated house with his wheelchair-bound 81-year-old mother.He was said by the prosecution to be infatuated with Miss Brewer but told the court she was like a big sister to him.He had kept out of the dispute until witnessing the front garden confrontation between Miss Brewer and Mr Siveter in April which lead to his number being written down.Miss Brewer telephoned police to complain and then telephoned Hughes, who returned with a gun looking for Mr Siveter.After being told he was not home, he banged at the door and demanded Miss Hart open it, calling out: "Come out bitch."Miss Brewer, who could be heard pleading "No", became hysterical as shots were fired, the court was told.Aftab Jafferjee, prosecuting, said: "This defendant did what he did precisely because of the underlying animosity and him empathising with Angie Brewer."Hughes had been heard telling her: "I will do anything for you, I will cut off my arm or leg if I had to."Mr Jafferjee added: "She will have a huge moral responsibility."The killing took place against a background of a long-running and ugly neighbour dispute that had been festering for some months. It can only be described as an execution."© Independent Television News Limited 2008. All rights reserved.