By Chris Summers
A woman has been jailed for four years for supplying her brother with a false alibi on the night he murdered a wealthy London banker. But what drove her to lie to the police?
Loyalty is a much-admired quality in modern society and the desire to protect a close relative or a lover is a powerful motive.
But the case of Laura Campbell proves what can happen when someone puts family loyalty ahead of respect for the law.
Damien Hanson was released from prison in August 2004 after serving seven years in jail for shooting a man during a robbery.
His sister Laura, then aged 18, hoped he would go straight.
But three months later, he went to her, spun her a story about the night of 29 November, the night when City banker John Monckton was stabbed to death and his wife attacked during a raid at their Chelsea home.
Hanson said he had been in a fight and asked his sister for an alibi, which left her torn between her love for her brother and her suspicions that he was lying.
Lord Archer - jailed for four years for lying during his 1987 libel case against the Daily Star
Maxine Carr - jailed for three-and-a-half years after lying to police investigating her lover Ian Huntley
Sade Adeyoola - teenager was given two-year detention order after trying to provide her sister, Kemi, with a false alibi. Kemi got life for murder.
Maya Devani - solicitor jailed for a year for helping smuggle a letter out of Belmarsh prison. The letter related to a false alibi
Louise Austin - given a suspended sentence after providing a false alibi to her friend, Soham police officer, Brian Stevens, who was jailed over child porn
Billy Dunlop - lied at his own murder trial, at which he was acquitted. Was later jailed for perjury. After change in the double jeopardy law he was also convicted of murder and given life sentence.
When, two weeks later, Hanson was arrested for the murder of John Monckton and the attempted murder of his wife Homeyra, she insisted he had been with her that night between 6pm and 10pm.
But she went further and claimed they had both been at the home in Brixton, south London, of her workmate Sade Haye.
But Miss Haye had not agreed to go along with their story and she told the police the truth, that neither Hanson nor his sister had been at her home that night.
By now Campbell was cornered.
She knew that to change her story at this point would "drop him in it".
Gradually evidence stacked up against Hanson but she stuck with her story, repeating it in a statement to police and again at the trial at the Old Bailey in November 2005.
Before the trial she contacted Miss Haye and tried to pressure her into saying Campbell and Hanson had been with her, but Miss Haye refused to cooperate.
Campbell was arrested in May this year and charged with perjury and conspiracy to pervert the course of justice.
Mr Monckton was killed in the attack while his wife survived
She stuck with her story right up until a week before her trial was due to begin, when she changed her plea to guilty.
In the meantime, Miss Haye became pregnant and gave birth three months prematurely.
Despite the stress, she was still prepared to give evidence against her former friend.
Judges do not look kindly on witnesses lying in court, especially during a murder trial at the Old Bailey.
Sentencing her, Judge Charles Byers said: "You and anyone in your position must understand that, however tempting it must be to lie on behalf of your loved ones, to do so is a very serious criminal offence.
"It taints the very fountain from which justice springs and, in a civilised society, we all rely on truth and justice.
"It's no mitigation that you were doing it out of love or misplaced loyalty."
Laura Campbell's defence barrister, Andrea Brown, accepted her client's jail sentence, not only because she said she must be punished but also because it would send out a deterrent to others.
But she said her client had since become a born-again Christian and had come to terms with her brother's crime and her role in it.
Ms Brown had earlier asked the judge to bear in mind her age - she is only 20 - and the effects her brother's actions have had on the family.
A spokeswoman for the Crown Prosecution Service said: "Conspiracy to pervert the course of justice is a very serious offence which actually carries a maximum sentence of life.
"It is taken very seriously and it is vital for public confidence in the criminal justice system that people tell the truth."
Detective Chief Inspector Alistair Tully, who led the Monckton murder inquiry, said: "Laura Campbell was willing to put her liberty at risk in order to protect her brother. The sentence given today will be a strong deterrent to others who are prepared to lie to police.
"Her lying caused extensive additional work to the investigation team and may have resulted in an evil man being set free to kill again."