A teenage girl was jailed for life today for stabbing a man to death during a Bristol carnival because he had been lecherous towards her and her friends.

Justice Roderick Evans, at Bristol Crown Court, said he hoped that, in handing down the minimum term of 12 years, it would deter other teenagers from equipping themselves with knives.

April Bright was just 17 when she stabbed Mohammed Muse Hassan, 35, in the neck with a knife at the St Pauls Carnival in Bristol on September 16 last year.

Bright, now 18, of Wilder Street, St Pauls, stabbed Mr Hassan in the neck in an alleyway next to the Criterion pub in Ashley Road at around 2.45am.

Earlier in the evening, Mr Hassan and his Somalian friends had made lecherous and inappropriate comments towards Bright and her friends in a takeaway next door to the pub.

Sentencing Bright, the judge said there was no excuse for anyone to arm themselves with a knife.

"When you went out on carnival night you took with you a knife, that you told the jury was for your own protection," he said.

"That is no possible justification for taking a knife.

"The carrying of knives is a matter of grave public concern and the presence of knives on our streets in clubs, pubs and in the hands of young people of your age so often leads to serious injury or in this case death.

"A slight, an insult, an inappropriate behaviour, real or imagined, so often leads to the production of a knife and to the consequences in this case."

Bright, who admitted manslaughter but denied murder, wrote a letter to the judge, saying she had not meant to kill Mr Hassan.

In mitigation, Michael Fitton QC admitted this was the first time she had expressed remorse over the killing.

During the case the jury was shown CCTV images of Bright and Mr Hassan as they went in and out of the Criterion pub amid swarms of carnival-goers in fancy dress.

The CCTV also caught Mr Hassan, moments after he was stabbed in the alley, stumbling through the party-goers, clutching his blood splattered neck, and collapsing on the steps outside the pub.

Bright was also seen gesticulating over his body, saying "Let him die."

Mr Fitton said his client had been diagnosed with ADHD while in prison on remand and was now taking medication which enabled her to co-operate more fully.

Outside court, Mr Hassan's family, speaking through a family friend, Prince Abdul Aziz, said: "Mr Hassan was a fantastic guy, caring and the first to offer help to others. He will be sorely missed.

"While we are pleased his killer has been found guilty, this is not a day of celebration because we as a family are sentenced to a lifetime of sadness.

"We hope that his death and the prosecution that followed will deter others who may wish to harm or kill innocent people."

The investigation by Avon and Somerset Police led to 1,000 people being interviewed and 800 witness statements being taken.

Detective Chief Inspector David McCallum said: "We are pleased that justice has been served and we would like to pay tribute to the family of Mr Hassan, who behaved with impeccable dignity.

"It is really easy to inflict fatal injuries with a knife and, when you carry a knife, when there is any sort of conflict it is easy to pull it out.

"My message is just think about it – this is a man whose life has been taken away and a young girl who will spend some of the best years of her life in custody."