Image copyright chieferu Image caption The review will help to determine whether there is any risk to the criminal justice process

More than 30 criminal investigations including 21 sex attacks are being reviewed after a forensic scientist apparently botched examinations.

Scotland Yard said a member of staff from its Forensic Services allegedly failed to carry out tests and lied to investigators about progress.

A total of 33 inquiries between 2012 and 2017 are affected - 21 rapes and sexual assaults and 12 violent and drug-related crimes and burglaries.

An internal review is under way.

All the work of the scientist, who was suspended on 26 March, has been audited and the Met said it is "satisfied that there are no other instances of undeclared casework".

All victims in the affected cases have been contacted, where it has been deemed appropriate to do so, police said.

A spokesman for Scotland Yard said: "In the case of the investigations into rape and sexual assaults, victims have been contacted by a sexual offences investigative techniques officer."

The review comes amid a national crisis in forensic services following the closure of the publicly owned Forensic Science Service in 2012.

Techniques including analysis of DNA, fingerprints and digital evidence play a major role in a range of criminal investigations and the move forced police forces to either bring the services in-house or use private providers.

One firm, Key Forensic Services, collapsed in January, potentially affecting thousands of cases.

Another, Randox Testing Services, was hit by claims of manipulation of results.

Around 10,000 cases - three-quarters of which were drug-driving and the rest violent crime, sexual offences and unexplained deaths - were affected across 42 police forces.</s>Police have launched an 'urgent' review into the work of a forensic scientist as 33 criminal investigations were hit by suspected 'mishandling' of evidence.

The Directorate of Professional Standards said it is investigating allegations relating to the suspected mishandling of a number of examinations.

It is alleged that a scientist working within the Metropolitan Police’s Forensic Services did not complete thorough examinations.

A statement added that the scientist was alleged to have, in some cases, wrongly informed investigators about the progress of forensic examinations.

The scientist was suspended on 26 March as part of the investigation.

An internal review has found that 33 separate criminal investigations have been affected.

As many as 21 of these cases relate to investigations into rapes and other sexual assaults, Met Police confirmed.

The remaining 12 are investigations into violence, burglary and drugs offences, with all the investigations taking place between 2012 and 2017.

A statement read: 'All victims in the affected cases have been contacted, where it has been deemed appropriate to do so.

'In the case of the investigations into rape and sexual assaults, victims have been contacted by a Sexual Offences Investigative Techniques officer.

'In order to be reassured that this issue is not more far-reaching, we have completed a full audit of scientists’ workloads within the department, and are satisfied that there are no other instances of undeclared casework.

'This case has also been referred to the Forensic Science Regulator.'</s>An “urgent” review into the Metropolitan Police is taking place after it was revealed that 33 criminal investigations may have been affected by suspected forensics mishandling, Scotland Yard has confirmed.

The Directorate of Professional Standards is investigating after a forensic scientist working within the Met’s Forensic Services allegedly mishandled material in its laboratory.

More than half of the cases – 21 out of 33 – relate to investigations into rapes and other sexual assaults, while 12 are investigations into violence, burglary and drugs offences, the Met said.

It said the scientist allegedly “did not complete the requisite forensic examinations and in some case wrongly informed investigators about the progress of forensic examinations.”

The scientist was suspended on 26 March as part of the investigation.

The Met said in a press release: “An internal review has found that 33 separate criminal investigations have been affected. The cases relate to crimes whereby items were submitted for forensic examination between 2012 and 2017.

“We are urgently conducting a review to understand whether there is any risk to the criminal justice process and to take remedial action where necessary.

“All victims in the affected cases have been contacted, where it has been deemed appropriate to do so.”

It added that in the rape and sexual assault investigations, victims have been contacted by a Sexual Offences Investigative Techniques officer.

The force said it has completed a “full audit” of all its forensic scientists’ workloads “in order to be reassured that this issue is not more far-reaching”.

It said it was “satisfied that there are no other instances of undeclared casework.”

The case has also been referred to the Forensic Science Regulator.</s>An urgent review will be conducted into the Metropolitan Police amid allegations 33 cases were "affected" by forensics mishandling.

The Directorate of Professional Standards (DPS) is to investigate allegations relating to the suspected mishandling of examinations within the Met's forensic laboratory.

It is claimed a scientist working within forensic services did not complete the requisite examinations - and in some cases, wrongly informed investigators about the progress of the examinations.

The scientist was suspended on 26 March as part of the investigation.

A statement from the Met said: "An internal review has found that 33 separate criminal investigations have been affected - 21 of these cases relate to investigations into rapes and other sexual assaults; the remaining 12 are investigations into violence, burglary and drugs offences. The cases relate to crimes whereby items were submitted for forensic examination between 2012 and 2017.

"We are urgently conducting a review to understand whether there is any risk to the criminal justice process and to take remedial action where necessary.

"All victims in the affected cases have been contacted, where it has been deemed appropriate to do so.

"In the case of the investigations into rape and sexual assaults, victims have been contacted by a Sexual Offences Investigative Techniques officer."

A full audit was carried out into the scientist's workloads within the department, the Met said, to make sure there were no other instances of undeclared work.

The case was also referred to the Forensic Science Regulator.

It comes after it emerged that evidence in 10,000 cases may have been tampered with by rogue staff at a laboratory in Manchester.</s>More than 30 criminal investigations including 21 sex attacks are being urgently reviewed after a forensic scientist apparently botched examinations.

Scotland Yard said a member of staff from its Forensic Services allegedly failed to carry out tests and lied to investigators about how the work was progressing.

A total of 33 inquiries between 2012 and 2017 are affected – 21 rapes and sexual assaults and 12 violent and drug-related crimes and burglaries.

The force said in a statement: “We are urgently conducting a review to understand whether there is any risk to the criminal justice process and to take remedial action where necessary.

“All victims in the affected cases have been contacted, where it has been deemed appropriate to do so.”

All the work of the scientist, who was suspended on March 26, has been audited and the Met said it is “satisfied that there are no other instances of undeclared casework”.

The case comes amid a national crisis in forensic services, following the closure of the publicly owned Forensic Science Service in 2012.

Techniques including analysis of DNA, fingerprints and digital evidence play a major role in a range of criminal investigations and the move forced police forces to either bring the services in-house or use private providers.

One, Key Forensic Services, collapsed in January, potentially affecting thousands of cases.

Another, Randox Testing Services, was hit by claims of manipulation of results.

Around 10,000 cases – three-quarters of which were drug-driving and the rest violent crime, sexual offences and unexplained deaths – were affected across 42 police forces.</s>Former BBC DJ Tim Westwood has denied knowing that a murdered teenager who appeared on his TV show rapping about stabbing rivals had any links to London's gangs or violence.

Mr Westwood has also denied profiting from enthusiastically promoting drill music on his YouTube channel - despite being a genre of music which celebrates gang life and focuses on attacking rivals.

Rhyhiem Ainsworth Barton was a member of the masked Moscow17 crew from Kennington who are involved in a violent feud with rivals the Zone 2 gang from nearby Peckham.

The 17-year-old, who was shot dead in the street on Saturday, appeared in a mask alongside Westwood last year in a rap video viewed on YouTube more than 170,000 times.

Westwood called Moscow17 'legendary' before they rapped about 'splashing' rivals - slang for stabbing someone repeatedly until they pour with blood - in a film where they appeared to be smoking cannabis.

Today he said: 'The artists featured on TimWestwoodTV are rap groups and we have absolutely no knowledge of any alleged gang affiliation'.

Today the former BBC DJ paid tribute to Rhyhiem, calling him a 'very talented young artist', but denied he knew that he was involved in the world of South London gangs.

He said: 'For the avoidance of doubt, there is no payment or fee to feature on TimWestwoodTV.

'Tim Westwood TV provides an opportunity for young people to pursue their aspirations and dreams of a having a career as an artist and gives them an outlet for their talent'.

Rhyhiem, who used the name GB, was also on a leaked list of rappers Scotland Yard believed was promoting violence and goading rivals in online videos, according to The Times.

Mr Westwood said they have no knowledge of a Metropolitan Police database', adding: 'The police have never contacted TimWestwoodTV over any video on the channel. We support any initiative that would stop the violence'.

Her son's murder was one of five shootings in London over the Bank Holiday weekend including a botched drive-by where a 13-year-old was blasted in the face as he walked along the high street in Harrow with his parents.

There were also three fatal stabbings in Liverpool, Luton and Macclesfield, Cheshire.

Rhyhiem's murder emerged after paramedics and police were called to reports of gunshots on Cooks Road in Kennington, south London, on Saturday at just after 6pm.

Rhyhiem was found on nearby Warham Street with a gunshot injury.

The 17-year-old rapper had 'so much potential', his mother said as she tearfully told of her 'handsome boy.' Ms Morgan called for a stop to the violence.

Speaking at the scene of the crime on Sunday, she said: 'Let my son be the last and be an example to everyone. Just let it stop. What must be, must be.'

Ms Morgan said her son was not in a gang and he had been 'trying to make a difference' by learning to work with children.

The following day, an innocent boy of 13 was accidentally shot in the head as he walked through Wealdstone, northwest London, with his parents.

The boy was the youngest victim of the wave of gun, knife and acid attacks across Britain over a bloody Bank Holiday weekend.

The teenager was an innocent bystander who had been walking down the street with his parents in Harrow, north west London, when he was hit by shotgun pellets.

He was caught in the crossfire when a 15-year-old was attacked at around 1.15pm on Sunday in High Street, Wealdstone.

Scotland Yard said the older boy was found to have suffered head injuries, caused by a number of shotgun pellets.

Police were alerted to the second boy injured nearby minutes after the 13-year-old boy.

Detective Chief Superintendent Simon Rose, Harrow borough commander, said: 'It would appear that the first victim was approached by two male suspects, one in possession of a shotgun - and shots were fired, injuring him and an entirely innocent member of the public.

'This was a callous, reckless and brazen act, without any thought by those responsible for the fact that there were families with children and people in the High Street enjoying their weekend. This was quite simply appalling.'

Last night a crowd of around 100 people gathered outside the victim’s estate in Kennington after the family had a private meeting with Sadiq Khan, who joined prayers for the 17-year-old gunned down in the street.

They then marched on neighbouring Peckham where Rhyhiem's Moscow17 gang is involved in a bloody feud with rivals Zone 2.

The London Mayor and the Met face a crisis after days of violent attacks in the capital including 11 gun, knife and acid attacks in the capital in recent days.

Last night there were more knife attacks in Hackney, Woolwich and Twickenham.

Last night a 16-year-old in Hackney was stabbed repeatedly with a machete after a fight on the Nightingale Estate at 4pm. Another victim, a man aged 18, was treated for leg injuries.

Another victim, in his late teens, was stabbed in the leg during an evening rush-hour incident near Woolwich Arsenal station, south-east London.

Police had again received reports of a fight, and a man was later arrested on suspicion of possessing an offensive weapon.

Less than two hours earlier, police in west London were called to The Embankment, Twickenham, to a teenager with a non-life threatening stab wound to his arm.

Rhyhiem Barton's mother blamed the police for her son's murder - saying they failed to protect him.

The teenager, who was the 62nd victim to be killed in the capital so far this year, is said to have been a member of the Moscow17 crew from Kennington who are involved in a violent feud with rivals Zone2 from nearby Peckham which has escalated through various YouTube videos.

Last year he appeared alongside Tim Westwood in a YouTube rap video where he was seen wearing a balaclava and a hoodie, waving a spliff around as he spoke about ‘splashing’ rivals - slang for stabbing someone repeatedly until they pour with blood - and bragged his crew is ‘known for capping’ its enemies which means shooting someone.

Yesterday his godmother Lacey Main called for YouTube to take responsibility in a packed public meeting on knife crime attended by local Labour MPs Harriet Hartman and Neil Coyle, along with Tottenham MP David Lammy and Sophie Linden, the Deputy Mayor for Policing and Crime.

She said: ‘Why do they put the music on YouTube? Take it out.

‘You have the authority, all of you sitting down there.

‘Every time they put a video up - shut it down.

‘These children have no talent. They are actually cowards.’ She went on: ‘If it comes from a gang, bring it down.

‘All the police know the gangs, they know about these videos, boasting and challenging each other and they know what they lead to.

‘They lead to evil, they lead to murder like this one. Don’t give them the platform, don’t give them the satisfaction.

‘The comments under these videos of threats and challenging people to do violence say things like “you are drilling hard.”

‘I wrote a message under one of these videos saying how foolish it was, and they just posted it again elsewhere so nobody could see my comment.

‘I have been telling police about this for three years but they do not work with YouTube, Snapchat, any of them. No one takes responsibility and there is blood in the streets.

‘Every time they put up a video bragging and boasting it should be taken down before this happens again.

‘Then the youths, they come to this area and film themselves on their rivals’ turf so the other group responds. It escalates and now my godson is dead.’

Tragic death toll: The rising number of lives taken on the streets of London in 2018

1 January, Steve Frank Narvaez-Arias, 20: Stabbed in the chest on New Year's Day at a flat party in a council estate off Old Street in Islington, north London. After moving to the UK from Ecuador, the 20-year-old was reading physics and aerospace at Hertfordshire University and hoped to become a pilot

3 January, Elizabeta Lacatusu, 44: Found bleeding to death on Norfolk Road, in Ilford, after she had her throat slashed. She worked at a restaurant in the east London town and was returning home when she was stabbed to death

6 January, Vijay Patel, 49: Mr Patel was beaten to death in Barnet

8 January, Daniel Frederick, 34: Daniel was killed metres from his home in Hackney after attending a hospital appointment for his pregnant partner

11 January, Harry Uzoka, 25: Harry, who was on the books of Premier Model Management and had modelled for brands including Mercedes and Zara - was stabbed in Shepherd's Bush. Neighbours reported a shout of 'hand it over' in the melee which involved several men

29 January, Juan Olmos Saca, 39: Died six days after being found stabbed at an address in Peckham

31 January, Lily-Mai Saint George, one: One-year-old Lily-Mai was found dead in Haringey. The Met Police say her cause of death remains unknown

31 January, Khader Saleh, 25: The 25-year-old was stabbed in the Hammersmith and Fulham area

3 February, Kwabena Nelson, 22: Ambushed in Tottenham in the early hours where he was fatally stabbed

5 February, Juan Olmos Saca: Died in hospital after being stabbed in Peckham

12 February, Bulent Kabala, 41: The taxi driver was shot dead in a 'targeted hit' on a roundabout in Barnet

13 February, Saeeda Hussain, 54: Found with critical injuries at an address in Ilford and pronounced dead at the scene

15 February, Mark Smith, 48: Mr Smith was found injured in Chingford, and died shortly afterwards

17 February, Lewis Blackman, 19: Lewis, who grew up on the Peckwater estate in Kentish Town, was killed in Kensington. Witnesses told how a gang of about eight youths, some armed with sticks, shouted 'let's chase him down', before he was stabbed

17 February, Josef Boci, 30: Jozef was beaten up in the street in Greenwich and died in hospital

19 February, Rotimi Oshibanjo, 26: Rotimi was fatally stabbed inside a property in the Halliday Square housing estate

20 February, Sadiq Mohamed, 20: The aspiring accountant was found with serious stab wounds in Malden Road, in Belsize Park

20 February, Abdikarim Hassan, 17: Abdikarim died in the street after being attacked in Camden

25 February, Michael Boyle, 44: Stabbed in Southwark. Mr Boyle, from Galashiels, Scotland died of multiple organ failure after being stabbed at a property in Southwark. He was found on February 25 but died on March 10

5 March, Kelva Smith, 20: Found stabbed in South Norwood, Croydon and pronounced dead at the scene

5 March, Laura Cecilia Navarrete De Figueira, 47: Police launched a murder investigation after Laura Cecilia Navarrete De Figueira was found with stab wounds at her home in Twickenham. An hour earlier the body of her husband Figueira de Faria and the bodies of Claudio, 10, and Joaquin, seven, were discovered on the beach at Birling Gap, in Eastbourne, East Sussex

12 March, Julian Joseph, 36: Murdered in Lewisham, cause of death as yet unknown

13 March, Nikolay Glushkov, 68: Russian businessman was found dead in his home in New Malden. He died from compression to the neck

14 March, Lyndon Davis, 18: The youngest to have been killed in March, was found suffering from a single stab wound in Chadwell Heath, east London

14 March, Joseph Williams-Torres, 20: Killed as he sat in a stationary car in Essex Close, Walthamstow

16 March, Naomi Hersi, 36: Stabbed in Hounslow. Hersi, who lived as a trans woman called Naomi, was pronounced dead at the scene after being found with knife injuries in Hounslow

17 March, Russell Jones, 23: Ambushed outside shops near Ponders End station, in Enfield and stabbed and shot to death

18 March, Tyrone Silcott, 42: The father-of-two died from knife wounds after a St Patrick's Day party. It is alleged the car mechanic got into a row over two girls at a party in Homerton and was attacked

19 March, Balbir Johal, 48: Died after being stabbed in Southall

19 March, Jermaine Johnson, 41: Found with stab injuries and pronounced dead at the scene in Walthamstow

20 March, Beniamin Pieknyi, 20: Believed to have jumped in to the fight in a bid to save his friend during the altercation at the Stratford Centre in east London. The 20-year-old, who only arrived in Britain two months ago from Romania, died in his best friend's arms after being chased and stabbed by a gang in the busy shopping centre

25 March, Abraham Badru, 26: Gunned down in Hackney. The university graduate, who was murdered in Dalston, east London, was awarded the National Police Bravery Award in July 2009

26 March, David Potter, 50: Found stabbed to death in a property on Tooting High Street

29 March, Reece Tshoma, 23: Reece, from Barking in east London, was stabbed in the neck in Greenwich before being rushed to hospital by his friend where he died

30 March, Leyla Mtumwa, 36: Leyla was found dead with stab wounds to the neck and chest at an address in Haringey

1 April, Devoy Stapleton: Stabbed at as he made his way home from a night out in Wandsworth. Police found him in a pool of his own blood after being called to the middle-class suburb of Earlsfield, south west London

2 April, Tanesha Melbourne, 17: Tanesha was gunned down near her home in Tottenham, north London in front of horrified friends and family. It is thought she was caught in the crossfire of a ruthless gang war

2 April, Amaan Shakoor, 16: The teenager was shot in the face in Walthamstow, north London, and police have now confirmed he died from his injuries in hospital

4 April, Henry Vincent, 37: Burglary who died from stab wound after raiding pensioner's house

4 April, Israel Ogunsola, 18, dies in Hackney after being stabbed. The victim approached police who performed first aid but he died at the scene after 25 minutes.

12 April, John Maclean, 35, stabbed at a flat in the Isle of Dogs. A 25-year-old has been charged with his murder.

15 April, Raul Nicolaie, 26: Found at with stab injuries in Colindale, north London. A 34- year-old woman was arrested at the scene on suspicion of murder

15 April, an unnamed woman in her 30s was stabbed to death in Sudbourne Road, Brixton, south London. A man in his 20s has been arrested on suspicion of murder.

16 April - Sami Sidhom, 18, is stabbed to death in the street in Forest Gate.

21 April - Man, 20, named locally as Kwesi, was stabbed to death about a hundred yards from Jeremy Corbyn's home in North London

23 April - Aaron Springett, 32, died after a street fight outside Paddy Power bookies in Morden

May 1 - A man in his thirties is shot dead outside Queensbury Tube station.

May 5 - Rhyhiem Ainsworth Barton was murdered on Warham Street, Southwark
The Metropolitan Police of London announces a review of 21 rapes and sexual assaults as well as 12 other offences including violence and burglaries over inadequately performed "undeclared casework" by a forensic scientist.