The younger sister of the teenager convicted of murdering the Golders Green pensioner Anne Mendel was jailed for two years last Wednesday for providing a fake alibi.

Sade Adeyoola, 16, a prolific shoplifter like her 18-year-old sister Kemi, was convicted of conspiracy to pervert the course of justice by trying to concoct an alibi about where Kemi was at the time of the murder on March 14 last year.

After returning from a visit to a Hendon travel agent, Leonard Mendel found his wife of 50 years dead in the hallway of their home in Elmcroft Crescent. She had been stabbed 14 times in the back, chest and arm.

At the Old Bailey last week, Judge Richard Hone QC told Sade: "You and your sister are intelligent, dishonest and manipulative with no scruples when it comes to looking after your own interests.

"The offence strikes at the very heart of the criminal justice system. False evidence can lead to a jury to a fundamental miscarriage of justice and needs to be countered by appropriate punishment." At the end of last month, the Old Bailey heard how Kemi, who was 17 at the time of the murder and was sharing a flat with her sister in Belsize Square, Belsize Park, was sentenced to a minimum of 20 years in jail. Judge Hone said Kemi, who had written a plan on how to murder a defenceless woman, had wanted the experience of killing someone to possibly help her write a story, but more likely so she could boast about it.

She had told police she had been trying to recover a lost purse at the time of the murder. During telephone calls to Kemi in prison, Sade agreed to meet another prisoner to arrange a bogus witness to come forward.

The court heard that Sade still believed her sister innocent of the killing.

Judge Hone ordered the lifting of a court order which prevented the identification of Sade due to her age.