it's gold again, the triple triple! usain bolt is to hand back one of his olympic gold medals because a team—mate tested positive for a banned substance. and the woman in charge of british vogue is to step down after 25 years at the heart of the fashion industry. and coming up in sportsday on bbc news, will liverpool make it to their second wembley final in two years? they're playing southampton in the second leg of the league cup semifinal. good evening. we start tonight with a special report on the marked increase in knife crime. an investigation for bbc news at ten has found that, last year, a knife or blade was used in a crime every 16 minutes somewhere in the uk. the number of incidents involving machetes has risen by over 60% in the past the years. the information was provided by police forces in england and wales. and records show there were at least 2,300 victims of knife crime last year aged 18 or younger, a rise of 45% over three years in england and wales. our special correspondent ed thomas, cameraman phil edwards and producer noel titheradge have produced this extended report. a warning that it does contain some explicit images. i'm not going to run and lose my respect. i'd rather get stabbed than run. they chased him into that alleyway, and ijust seen them stab him. turned our lives upside down, and it's the ripple effect. it goes on, and on, and on. five years' time, i could be injail, i could be dead. i could be the biggest drug dealer in liverpool, you never know, do you, till it happens? tonight, it's liverpool. but this story could be told in many cities. it's one of knives, fear and wasted lives. starts from, you know, selling a bit of weed, to selling a bit of class as. when did you start carrying knives? 12. can ijust see what you had, then? that's not a knife, that's...? that looks a bit more than self—defence to me. scare tactics. the bigger, the better. this man, in his 20s, says he sells drugs and won't leave home without a knife. i've faced knives, faced guns. i've been shot in the leg. have you stabbed someone before? yeah. that's really disturbing. i'm disturbed, mate. we're all disturbed, because we're all the same. it's hard around here, the cycle never breaks. for these teenagers, this is how the cycle begins. it happens early, from when you go to school, you argue with other kids. the next thing you know, you end up getting stabbed or something. getting stabbed ? you have to have a blade, because people around you, they have blades. are two rolling with blades? can we see? what is it? chopper. chop hands off. do what with it? chop hands off. do you know what would happen if the police caught you with that? yeah, i'd get nicked. and do you know what would happen to you? yeah, probably go to jail. 0n merseyside, knife crime has risen by a quarter since 2012. since then, across england and wales, at least 7800 victims were aged 18 and under. i have had to stab a couple of kids, because they've been chatting sort over social media about me. about my dead friends. and what damage happened to those kids? sliced face. scarred for life? yeah. so they wake up and think, you know what it is, i'm not going to say that no more, look what that caused me, they see the scar on their face. this is completely wrong, this is unacceptable. karma, it works both ways. i know my karma is probably to catch me one day. when it happens, it happens. i'm not going to run from it. i'm going to fight back. the pain caused isn'tjust physical. i could never walk the streets, right here, right now, without having flashbacks, memories of some sort. misery. abuse. torture. chloe wanted to talk openly. atjust 16 she was groomed by a liverpool gang. she faced knives, guns, beatings and sexual abuse. one of my boyfriend at the time's friends pulled up on me, in the car. gang member? yeah. and said, i can take you to him. so i got in. he went to the park and proceeded to lock the doors of the car. at that instant, i knew that i weren't going to see my supposed boyfriend. he proceeded to tell me to take my knickers down, or i was getting it, right here, right then. what this gang do to you and your life? i basically have to fight myself, every day's a battle in my head to try to get through what i've gone through. and the consequences of the violence echo across this city, changing lives. you've got kids who won't go in to the next street, and i mean literally the next street, because they're scared of the gangs around here. here, they work with children from the age of five, educating kids about street violence that they believe is mostly unseen and underreported. doesn't even make the news no more in liverpool. unless it's a real bad case. but we know about it, we get to find out all of the stuff on the streets. we know what's happened, and it's a lot, lot more than what the stats are saying. what those stats do tell us is that, on average, every 16 minutes a knife or blade is used in crime across the uk. in liverpool, trauma nurse robjackson treats the victims. we've had people having their hands hacked off for £70 cannabis bills. he photographs what he sees. the results can be horrific. seen people's faces hacked to bits, we've seen people who had their guts, basically, split open. his pictures are shown in schools, a warning to children who carry knives. takes one stab wound to kill you. it doesn't have to be five or six stab puncture wounds, it can be done to one single wound, that can be enough to kill somebody. my son, joseph, was stabbed to death at a youth centre he'd gone along to to watch his friends do a band practice. my life just stopped that day. he was my first born child. he was... he was my... joseph lappin was 16 when he was stabbed once, through the heart, in 2008. he'd never been in a gang. he'd never carried a knife. i was just starting to see glimpses of the man that he was going to become. he was just starting to mature. all that stopped the day that this lad decided to go out with a knife. sincejoseph‘s death, more than 11100 people have been stabbed and killed with a knife across england and wales. how many more young lives are waiting to be devastated? it's the way it is, we failed a long time ago. normal lives aren't meant for us. street life's meant for us. merseyside police declined to be interviewed for this report, but told us knife crime was a national issue without any easy solutions. ed thomas, bbc news, liverpool. that special report from liverpool by ed thomas on the marked increase in knife crime over the past three years. president trump is signing more executive orders. he says today is his big day on security and he's confirmed that he's taking action on one of his most prominent campaign promises, to build a wall along the us border with mexico. tonight mr trump said he expected construction to start within months and that planning was already underway. 0ur correspondent james cook reports from the us—mexico border. donald trump signature‘s pledge is now one step closer to reality, with a stroke of his pen, the new president ordered the construction of a great wall on the mexican border. it would begin, he said, within months. a nation without borders is not a nation. beginning today, the united states of america gets back control of its borders. we're going to get the bad ones out. the criminals and the drug deals and gangs and gang members and cartel leaders. the day is over when they can stay in our country and wreck havoc. strengthening and extending the existing barrier on this frontier will be hugely expensive. mr trump has always insisted that mexico will pay, but mexico say it won't and the president now admits american taxpayers will have to cough up first. ultimately, it will come out of what's happening with mexico. we're going to be starting those negotiations relatively soon and we will be in a form reimbursed by mexico. so they'll pay us back? yes. absolutely. 100%. so the american taxpayer will pay for the wall at first? all it is is, we'll be reimbursed at a later date. but here in the mexican border city, business leaders are worried about the impact on trade and sceptical about the president's plans. the problem is that the majority of americans are not really familiar with the border and, consequently the idea of a wall seems to be appealing. we already have one. we call it the tortilla curtain, but the truth of the matter is that, you know, i think that's a symbol. this fence at the pacific ocean is the very start of the land border between mexico and the united states and president trump has always said he wants to build a much taller, a much better, much bigger wall, stretching all the way from here, nearly 2,000 miles to texas. # this land is your land # this land is my land... but even in liberal california there's backing for president trump's hardline on immigration, not least from these supporters who call themselves the trumpettes. i think it's a good thing. you know i always say my scripture is, "i sought for a man who build a wall." i was reading that the other day and it just stuck out in my spirit because we need protection, and i pray for america and i pray that god will shore up the border of our nation. as well as the wall, president trump is promising to deport immigrants who commit crimes, to cut funding to states like california which refuse to arrest most illegal aliens and to hire 10,000 more enforcement agents. his actions are bold, sweeping and intensely divisive. james cook, bbc news, on the us—mexico border. 0ur north america editor, jon sopel, is at the white house. the president promised a big day on security, but it has gone way beyond that? way beyond that. he has been talking about much wider issues. talking about some enhanced interrogation techniques that may be appropriate to be used either cia when questioning terrorists in future. he was asked in that interview, do you think that water boarding works? he said, i want to do everything within the bounds of what you are allowed to do legally, but do i feel it works? absolutely i feel it works. he talked about the need to fight fire with fire. he said he would leave it to his defence secretary and cia chief. the cia chief has been more sympathetic towards it. the defence secretary said, you know what would be more effective? give me a packet of cigarettes and two bottles of beer and the person i am interrogating is likely to respond better to that. there is also a document circulating, which looks like a d raft circulating, which looks like a draft executive order, which talks about all of those things that seemed to belong to a different political era, enhanced interrogation, water boarding, all of the things that were from the bosch era... george bush era war on terror seemed to be considered again. the prime minister has decided she is prepared to publish a more detailed government paper on the strategy for brexit. theresa may said she recognised there was an appetite for a white paper after number of conservative mps joined labour in asking for a paper to be published. the supreme court ruled yesterday that mrs may could not begin the brexit process without pa rliament‘s approval. 0ur deputy political editor john pienaar reports. remember him in the goggles? a once dominant pm out on his ear when britain chose brexit. what happens next? david cameron's doing charity work now, today visiting a medical research lab. reporter: are you worried about defeat prime minister? now, his successor‘s got her hands full with the tactical battle for brexit. and today, theresa may kept a half step ahead of her critics. she'd outlined her brexit game plan in a big speech, they wanted it in black and white. and as the time came for questions... ..a concession. she'd held off promising mps a policy paper, but now... i can confirm to the house that our plan will be set out in a white paper, published in this house. jeremy corbyn was caught on the hop. could we know when this white paper is going to be available to us? but he ploughed on. will they withdraw the threats to destroy the social structure of this country by turning us into the bargain basement she clearly threatens? but the prime minister's kept the initiative and the brexit paper is unlikely to tell mps more than they know now. it was an easy concession for theresa may to make, but tory mps, worried about brexit, welcomed it. she's also keen to appear ahead of the game when she visits donald trump in the white house later this week. and she told mps she won't duck policy differences. i am not afraid to speak frankly to a president of the united states. i'm able to do that because we have that special relationship. mps queued to offer issues where she could take on the new president. he must abide by and not withdraw from the paris climate change treaty. president trump has repeatedly said that he will bring back torture as an instrument of policy. when she sees him on friday, will the prime minister make clear that in no circumstances will she permit britain to be dragged into facilitating that torture? will the prime minister tell president trump that she is not prepared to lower our food and safety standards or to open health systems for privatisation? her answer, she and her government would stand their ground. we will put uk interests and uk values first. another former prime minister's been in brussels, tony blair knows getting close to the white house at the wrong time can end badly. mps on all sides are anxious theresa may remembers that lesson. john pienaar, bbc news, westminster. there's news tonight that royal bank of scotland, which is mostly owned by the taxpayer, is to set aside another $4 billion to pay fines for mis—selling. our business editor, simonjack, is here with more details. what can you tell us, simon? it's another massive body blow for rbs. they have been setting aside in the kitty to pay this monster fine for its role in selling risky mortgages. that kitty is now at $10 billion if you add in this 4 billion. this will put rbs in a bigger loss in 2016. the ninth year in a row that rbs has lost money. i should say this was not unexpected. nor is it final. the final bill may be much higher than $10 billion. rbs had hoped to settle all of this at the beginning of this month, before the new administration comes in. it remains to be seen whether the new administration is more 01’ whether the new administration is more or less lenient on foreign banks which have caused misconduct. it's frustrating for the management of rbs. very frustrating for taxpayers. it will be even further until we get our money back. as painful as this is, maybe we are taking one step towards the end of this very long, very dark tunnel, it seems to be it will be another couple of years, at least, many several years couple of years, at least, many several yea rs before we couple of years, at least, many several years before we get our money back. it remains to be seen. i expect that as early as tomorrow morning around 7.00am. 0k simon. simonjack there morning around 7.00am. 0k simon. simon jack there for us, morning around 7.00am. 0k simon. simonjack there for us, our business editor, with the latest on that business story. a brief look at some of the day's other other news stories. more than 4,000 people have been sleeping rough every night on england's streets. the latest figures show that while london has the highest number of homeless people, more than half of councils in england recorded a rise in rough sleepers compared to the previous year. a man arrested over alleged threats made against gina miller, the woman behind the brexit legal challenge, has been released on bail. the 50—year—old man was detained on wednesday on suspicion of racially—aggravated malicious communications. he has been bailed until mid—february. northumbria university has apologised and been fined £400,000 after two people nearly died taking part in a science experiment. the students were accidentally given enough caffeine for 300 cups of coffee, 100 times the intended dose. laws to prevent discrimination against women in relation to dress code in the workplace are not being properly enforced, according to mps. their report was commissioned after a receptionist was sent home for not wearing high—heeled shoes. rescue teams in italy have found more bodies in the ruins of a ski resort hotel that was hit by an avalanche last week. in all, 24 people were killed with 5 people still missing. 0ur rome correspondent james reynolds has been speaking to two survivors. how many of us will ever know what it's like to come back to life? on saturday vincenzo forti and giorgia galassi were pulled from the hotel. the couple had been trapped underground for 59 hours. this afternoon we met them at home, they told me what happened when the avalanche hit. translation: it felt like a bomb, i felt glass exploding and it felt as if an entire wall had hit me. somewhere underneath these tonnes of snow and debris they were jammed together in a tiny space. translation: i looked at vincenzo and he saw i was panicking, the first thing he told me was, "we have got to be calm. we just have to wait." i touched him to see if we were 0k, if we were injured. we were lucky, we were alive. i thought we would be trapped for a week. i didn't want to tell her. after two days, rescuers made contact with them. translation: when we heard a rescuer, it was as if an angel was talking to us. as if someone had come to pick us up, literally, from under the ground. i was born again. it was a miracle. ifeel as if i've been brought to the world for a second time. and this time not by my mum, but by god. they survived, but many others died. a week on, rescuers continue to search for those still missing under the snow. james reynolds, bbc news, central italy. british scientists have identified 14 new disorders affecting children after analysing the genes of thousands of children with rare, undiagnosed conditions. identifying the genes responsible should lead to a greater understanding of the serious disorders which affect the development of the brain and body and might eventually lead to treatments. 0ur medical correspondent, fergus walsh, has the story. caitlin, so nice to meet you. hello. a big moment for these two families, meeting for the first time. ten—year—old tamika and nine—year—old caitlin have the same newly identified genetic condition, called cdk 13 disorder. there are only 11 known cases in the uk. the girls are so alike, they could be sisters. living so close, we could have easily bumped into each other. do you think we would have gone home with the wrong child? looking at them, it would have been easy, they are so similar. it's quite amazing to finally come across somebody who also has a child so different to anybody else's child and yet, here we are, and they are like twins. they are. to look at them, they are so similar, aren't they? the developmental disorder affects the girls‘ learning and communication. why do you think you took the wrong child? tamika has good language skills, caitlin has only a few words. it gives me hope as well, seeing tamika talking so much. it definitely gives me hope that caitlyn‘s speech will form. this is where caitlin and tamika's genetic condition was identified, at the wellcome trust sanger institute, near cambridge. they mapped their genes and found an identicalfault in their dna, but the mutation was not passed on by their parents, so how is that possible? each of us inherits half our dna from our mother, through the egg and our father in the sperm. sometimes, when those genes are passed on, spontaneous mutations occur that cause rare developmental disorders in children. the older the parents, the more likely that is to happen. scientists here have identified 14 new developmental disorders and calculated that one in every 300 babies will be affected by a spontaneous genetic condition, not carried in their parents‘ dna. in the uk, that amounts to around 2,000 children every year. the research, in the journal nature, provides reassurance for many families all over the country. the discoveries end the long odyssey that these parents have had trying to find the underlying cause of their child's condition. it provides them with the risk for future pregnancies. which, for these conditions, is actually very low. and it provides opportunities for research into the causes and possible therapies that might be applied. katya was told last year that she had not passed on tamika's genetic condition and that gave her confidence to have another child, timo, who's unaffected. both families say being part of this research has been hugely rewarding. it's like belonging to a club or a new—found family. yes. it has felt like we've been, for the whole nine years, that we've just been on our own, that there's been no one else out there. but now, knowing that there are other families. all changed? yes, completely. yeah. fergus walsh, bbc news. usain bolt, the record—breaking jamaican sprinter, will have to hand back one of his nine olympic gold medals after one of his team—mates in the 4x100 metres relay at the beijing games, nesta carter, tested positive for a banned substance when samples were re—analysed. the gold medal was one of those which made up bolt‘s famous triple—triple, as katie gornall tells us. in a sport measured in fractions of a second, this was an astonishing feat of longevity. commentator: the triple-triple! he's done it. usain bolt‘s nine fold medals, at three different 0lympics, was unprecedented. now, through no fault of his own, that history has been tarnished. the reason lies with this man, nesta carter, bolt‘s team—mate in the relay at the 2008 beijing 0lympics. his start propelled jamaica both to gold and to a world record. but last year, carter's sample from these games was retested and today he was found guilty of doping. under the ioc rules, the whole team is now disqualified. it's an outcome that bolt has feared for some time. i asked him about it back in august, in his hometown of kingston. at any point, if i lose one of my medals, it'd be devastating and stressful, do you know what i mean? to know that, after all that hard work, this would happen. but i think the sport is in a really bad place now and the only place it can go right now is up. it must be hard as well because the triple—triple is such a special achievement? it's very, very, very special, but we'll see. fingers crossed. sadly, whilst bolt stood clean, his rivals have fallen around him. justin gatlin has been banned twice forfailing drugs tests. tyson gay has tested positive for an anabolic steroid and his fellow jamaican, asafa powell, has served a six—month ban. today, nesta carter was found to have taken the banned stimulant methylhexaneamine. you can't re—run the race, you can't get those medals back. and i think, in usain bolt‘s case, after what we saw in rio, we all now know that that was his last olympic games. so it's gone from those nine medals, that were unbelievable, to eight medals. but it's still unbelievable what he achieved in his career. bolt will now have to hand back one of his precious medals, still he'll retire with his legacy intact. katie gornall, bbc news. football, and southampton have progressed to the final of the english football league cup after beating liverpool at anfield. (a late goal by shane long secured the second leg of the tie, giving southampton a 2—0 aggregate win. hull city play manchester united tomorrow to decide who they'll face in the final. one of american television's best—loved stars, mary tyler moore, has died at the age of 80. he's probably sitting out there right now thinking that i'm... ..boy, i don't blame him. look what i did? 0h... in the 1960s, the mary tyler moore show was among the biggest programmes on us television. she also had some success in films, with an oscar nomination for ordinary people. she'd been seriously ill for two years and her representative said she died in the company of family and friends. one of the leading figures of the fashion industry, alexandra shulman, is stepping down as the editor—in—chief of british vogue. she's been in charge for more than a quarter of a century, making her the magazine's longest—serving editor. ms shulman said it was a hard to decision to leave the magazine, but she explained that she "very much wanted to experience a different life." 0ur arts correspondent, rebecca jones, reports. she persuaded the duchess of cambridge to appear on the front cover of vogue, following in the footsteps of the princess of wales, the singer and designer victoria beckham and the model, kate moss. i'm not keen on that. alexandra shulman has been in charge of choosing some of the most memorable images in british fashion. i mean, her leg does not look great in this. this is kind of like way too much union jack, the other one would be better to try. do you think? yeah. ijust thought that was more... had more movement to it or... well, it's not going to get my vote. 0k. we need cutting—edge beauty and a cutting—edge. .. and herformer deputy at vogue, susie forbes, knows about alexandra shulman‘s straight—forwa rd approach better than most. she's never been afraid to take risks and ruffle feathers and get people in the industry to improve on any wider shortcomings that she sees as something she should take the world to task about. such as? such as body image, diversity and, basically, just championing british fashion, and that's what they does all over the world. and vogue's publishers said she'd been the towering figure of the british fashion press throughout her time in charge, promoting designers likejohn galliano and alexander mcqueen. she's played a key role in nurturing and wearing british talent, including this dress by erdem. nonetheless, she stood out on the front row as the down to earth face of fashion. unlike other ultra—slim, ultra—stylish editors, she made her mark by looking normal and while she admitted to anxiety, she kept it well hidden, as a recent documentary revealed. you don't seem like someone who would carry much stress with you though? no, i know. it's amazing that, isn't it? i've never seemed like somebody who carries stress with me.