in which acid was sprayed inside a london nightclub in the early hours of this morning. now on bbc news, it's time for click. this week, fighting crime before it happens. and keeping warm in the arctic. oh, my god! i said keeping warm... 0h, forget it. we are now more surveilled than we have ever been. cities are covered in cctv cameras. authorities are gathering data on its citizens. it would be all too easy to confuse the real world with a sci—fi dystopia. mr marks, my mandate of the district of columbia pre—crime division. i'm placing you under arrest for the future murder of sarah marks and donald dubin, that was due to take place today, april 22, at 0800 hrs and four minutes. no, i didn't do anything. in the movie minority report, the pre—crimes unit race to arrest would—be offenders before they have a chance to commit their crimes. now, they use psychics but it turns out something similar is being attempted using big data. in chicago, where the violent crime rate has exploded, law enforcement has been forced to try out unconventional ideas to combat crime. authorities are attempting to combine various technologies in an effort to predict where and when violent crimes might occur. marc cieslak went to chicago to find out more. violent crime in chicago has seen a dramatic increase. radio: a 15-year-old male, shot in the neck. both shots fired at her. shots were almost indiscriminate. shots fired. we need a wagon with a body bag also. the drug industry is what helps them fuel the violence, by being able to pay for their activity. in 2016, 726 murders were committed in the city, a 19—year high. that's more than the number of murders committed in new york and los angeles combined. chicago is a city most famously known as the windy city. more recently, it has earned a nickname that few residents are proud of, though. they are calling it chiraq. that's because gun crime is so extreme in some neighbourhoods, they are comparing them to war zones. the issue has received increasingly negative attention in the us, with president trump tweeting, "if chicago doesn't fix the horrible carnage going on, i will send in the feds". but many believe that to fight crime in the city, first, the authorities must understand its causes. eddie bocanegra has for years worked to help young people surrounded by violence in the city. now a director of the ymca, he also serves on the mayor's commission for a safer chicago. good seeing you, sir. so this space here that you've got, what do you use this for? so we use this space for a lot of our kids, between the ages of 13 and 18. many of them who are in gangs. many of them who are on probation or parole. more importantly, kids who experience a lot of chronic violence. when you see the front page of a paper, saying a 15—year—old person killed someone else, these are the kids. gunshot victim. the response from chicago's police department is a new initiative, driven by technology, which aims to predict where crimes are likely to occur. the university of chicago's urban labs are assisting the police in its efforts to integrate this technology into its operations. we have a lot of expertise in analysing crime patterns and trends in the city, from years of working with data on the city of chicago. and so we are leveraging that expertise to really help the police department think about where it should be allocating its resources to be most effective. so what kind of data or information is it that the police are providing you with here at the crime lab? we have a number of datasets that we work with from them, including data on crime patterns, actual crime incidents, arrests, victimisations. a number of different methods of analysis are used, including machine learning and predictive analytics. this is software which takes large volumes of data and tries to identify trends and patterns. these trends can then help predict where a crime might occur next. this is a heat map of homicides in district 7. and we are looking at this year over year, from 2011 to 2016. and basically, what you see on the map is the darker the red, the more concentrated homicides were in a given area. what sort of factors are you finding are influencing crime in these particular neighbourhoods? yeah, so, most of the prediction that we're doing is space—based. so, yeah, it's locations that are nearby that are high—risk locations, like a 24—hour liquor store, a gas station, where people tend to congregate. the weather seems to be playing a very big role in the data. you know, we've just had a beautiful weekend and we just had significantly worse amount of shootings than we had previous weekends. the police are using these predictive tools to inform the deployment of officers and resources to areas where they think crimes are likely to occur. neighbourhoods in chicago's west and south side are some of the city's most violent. it is these neighbourhoods which have been chosen to test the technology in a pilot scheme. we are just driving through chicago's south side now. now, this is one of the areas which has experienced the highest incidence of violent crime, mainly gun and drug related. to see how all of this different kit works, i'm on my way to a police station which acts as a command centre, bringing all of the technologies together. heading up the project is deputy chiefjonathan lewen of the chicago pd. so this is our strategic decision support center. so this is where you bring all of your different technologies together? it is. this is the first time that this level of technology integration has been done, not only here, i think, but around the country. so what can we see on the screens we have got around us? so, all around us are various sensor inputs, cameras, gunshot detection. the screen behind you is something called hunch lab, which is a geographic prediction tool that brings a lot of data into a model to predict risk for future violence. so what you are seeing on these little boxes here are areas where the model is recommending that we deploy resources and implement strategies to fight some of the violence it is predicting. and then it is telling us that we should deploy resources, visit businesses, do foot patrol, various tactics. shot spotterjust very quickly triangulates possible gunshot events using acoustic sensors that are located throughout the district, and it shows the officer exactly where, accurate to within 25 yards, that gunshot event occurred. and you can actually play the audio of the gunshot event, which we'll do now. so here's an event with nine rounds fired. gunfire. and in this case, you can see the location is actually the back yard of a house, so that's going to be very accurate. so this is the decision support system and this is where everything comes together in one place. it will soon be available in the hands of officers on smartphones. so in this case, we are looking at a 911 call of a robbery thatjust occurred at 7600 south marchfield. there are four cameras within a 300 foot radius of that call. here is the real—time video from those cameras. these guys here, these are possible suspects, or... these are people that might possibly be involved ? potentially. how do we know that this is identifying the right people? we find that they are very accurate. we find when we test and measure them, that the model's recommendations, because we can backdate it, we can look at a known outcome period and see how it performs. and we know that it's picking the right people because we know that it is accurate. but does it make mistakes? of course. that's where the people come in. but some of this technology is proving to be controversial, especially this. it's called the strategic subjects list. where hunch lab is concerned with predicting crimes and locations, this list is concerned with predicting crimes and individual people. so this is a risk model. just like hunch lab is a place—based risk model, this is a person—based risk model that is looking at variables such as arrest activity, so have you been arrested for a gun offence in the past? have you yourself been shot? so it's using some crime victim data. is your trend line in criminal activity increasing or decreasing? what was your age at the time you were last arrested? it is using those variables. nothing about race, nothing about gender, nothing about ethnicity. it is using objective measures to determine risk for a specific person. it's basically telling us that this person is 500 times more likely than a member of the general population to be involved in a shooting, either as a victim or an offender. so in here, we can see his affiliations, his gang affiliations. he's a gang member. we can see also his, is this his arrest record that we can see here? his arrest record. you can see that he has a weapons arrest. he was arrested here for aggravated battery. he strangled somebody. so here's a first—degree murder charge. here's another arrest, this is a narcotics arrest. so the score estimates how much more likely an individual is to be the victim or the perpetrator of a violent crime. the police use this score to inform what they call intervention strategies. this is not designed to be a punitive tool. this is used to drive what we call a custom notification process, which is literally a site visit to this subject, to say, "you've come to our attention for these reasons. we want to get you out of the cycle of violence. we can offer you the following social services". maybe it'sjob training. maybe if they have children at home, it would be childcare services. "but also, if you don't leave the cycle of violence and you keep committing crimes, you're going to be subject to enhanced criminal penalties", because you're a repeat gun offender, for example. and can you see why, if police officers go and visit somebody out of the blue, it might seem like they are being victimised, for instance? everybody who has a risk score has committed a crime in the past. otherwise they wouldn't even be in the model. groups like the american civil liberties union, though, disagree. they aren't happy about the use of some of these technologies. the police showed us a database of people who have been involved in violent crime in the past, and an algorithm which suggests if and when they might again be involved in a violent crime. they pay that person a visit. what's wrong with that? the police show up with... oftentimes in large numbers, along with a number of social service providers. but what they won't say is what social services are offering. is itjust them or is it their entire family? what is the success rate once that occurs? the fact is, is that most of the people who are charged for... you know, if you take two people who are arrested for a simple drug possession, if one is white and one is african—american, the african—american is far more likely to be charged, maybe even convicted. we have seen that there has been, you know, in essence, a "once convicted, always guilty" sort of theme that comes out of this list. while there might be disagreements about the use of this technology, everybody i spoke to had similar ideas about an ultimate solution to tackling violent crime in chicago. it's got to be every, everybody that's a stakeholder in this coming together to solve the problem. what is really needed across this city is a commitment to community— based policing. i think a lot of it has to do with preventing, with healing, and creating a space where individuals can civically engage back into the community. well, that was marc and this is marc. fascinating story, i have to say. how do you get on to that list? the police said that the list is composed from people that have committed violent crimes in the entire state of illinois. that is the prerequisite for getting on? they only consider people who have previously committed crimes? yeah, if you've already committed a crime, especially a violent crime, you might end up on the strategic subjects list. well, interestingly, earlierthis week i spoke to dj patil. now, until recently, he was president 0bama's chief data scientist. i asked him about this and this is what he said. ihave... many, many deep concerns about the process of these things. the fundamental one is the transparency of the algorithm. very recently in the us, we had a case that was written up by propublica. what was being used was a number of variables that were very prejudicial. and specifically, your race, your background, your life experience. you know, these datasets of offenders, we also know, have oftentimes have an increased bias because of the way police enforcement happens, or is it happening in one neighbourhood versus another neighbourhood? now, do i think there is merit in the use of this data? absolutely. the way we saw it, and one of the reasons why we created the white house data—drivenjustice initiative, is that we realised that, hey, a huge amount of these people have other problems and we can help them. welcome to the week in tech. it was the week in which we learned that disney has filed a patent for humanoid soft—body robots. minecraft said it would allow content creators to sell their work online. and amazon promised to refund up to $70 million to parents whose children made in—app purchases without their consent. naughtyjohnny! it seems some hackers like waking up texans in the middle of the night. all 156 tornado warning sirens in dallas were turned on at once. sirens. officials haven't yet tracked down the person responsible for the midnight hoo—ha but say they were activated via radio or telephone signals. an oceangoing robotic snake has popped up in southampton. the eelume has cameras and sensors so it can perform maintenance work below the waves. could the boys in blue be about to go green? behold, the ford police responder hybrid sedan. the eco—friendly car features anti—stab plates in the front seat. but hang on, it's slower than the petrol model it is replacing in the states. and finally this week, little green people in your living room. globacore has released hololems, a virtual reality homage to ‘90s classic lemmings. guide your green—haired friends to safety across your worldly goods. just don't expect a refund for either in—app or real—world purchases. the arctic circle. beautiful. wild. and unforgiving. and for three days, home to four fundraising friends. they will traverse 100 kilometres over mountains and frozen lakes in temperatures as low as —30 celsius. what do you think? group leaderjames' daughter suffers from mitochondrial disease, and this trek is to raise money for a charity that helps children with the condition and their families. these guys are all senior tech geeks by day, so to help them on their quest, we've equipped them with some of the best bits of supercool tech. here we have all our technical equipment. some people think this is a lunchbox, but it's not. battery— powered heated socks. these are electric gloves. but which of these extreme weather gubbins will actually do the job in these punishing temperatures? suited, booted and sufficiently powered up, they head off into the wilderness. so it begins! one of the most vital gadgets we're using is this satellite communications device. so it's going to send connor's wife, my wife, john's wife, tuuka's girlfriend a text message to say everything's 0k. we are using some hand warmers. that's going to keep some of our tech kit that we've got in here from freezing up, particularly a load of battery packs that we've got. we've armed ourselves with a whole load of different battery packs. this one here is the ravpower, and it's designed to be worn. here we have the zerolemon power bank. you can see it is really sturdy. it is a little bit heavy but then again, it packs 30,000 milliamps. i'm going to hide the nomad tile trackable battery pack from james, who you can see behind me. i'lljust place it here. aha. there you are. wow, maybe i should have hidden it better. day one. sun setting. it's about 7pm. that is frozen honey. john's eating it. it's been a long day. tuuka, i think we made it just in time, my friend. quite exhausting. we're all knackered but... very happy to be at this wilderness hut that we just got to. i'm trying out the heated insoles today. the insole has gone into the shoe. the cable comes out the back. we plug a battery pack into there. here we go again. we've got the gopro mounted to the skis. we're headed off in that direction, about 34k, i think, today. the little gopro hero5 session was left out overnight. i thought we'd killed it and i went and kind of scraped the ice off it in the morning, pressed the button, boom, it's recording again. so it's like, 0k, that's seriously cool. i've been wearing a finnish smart watch that's been tracking my activity. as well as tracking your location, dropping a breadcrumb of gps coordinates as you move, so once you've done something, it goes, "how was that? was it excellent? was it very good? was it average?" yeah. i'm going to say that was poor. i'm just going to save that up on the touchscreen. the biggest thing i've found was that it gives you so much encouragement, you know, when you're wrecked and you're about to die after 12 hours. the heated soles in the boot are working quite nicely, giving me a bit of ambient warmth. so here we have the blaze spark infrared lens. keen to capture the northern lights, connor's got a smartphone night—vision adapter. flip in the device. into the charging socket. you download an app called blaze spark. very simple to load, and once you connect the camera, the app automatically starts and your phone becomes a magical infrared lens. ok, because we had to lug quite a lot of stuff across the arctic, there's some bits of kit we didn't take with us. it's the biolite campstove 2. it's got a fan inside it, so as you light the fire, it blows air through the bottom, causes it to really combust quickly. it's also got an integrated battery pack. and it actually converts heat into electricity and keeps the battery pack charged up. so this thing has got a usb slot and the phone is on charge. it's already 3% up. it's really, really, really cold. my feet are warm, on the plus side. this is a scientific test. this hand has got a heated glove on it. this hand doesn't. laughter. this one's really cold! this one isn't. that's actually nice. it's quite a lot of weight you're carrying and you can only charge them up from the mains, so if, like us, you're trekking out in the wilderness for a few days, they are not going to see you through. would you pay $500 for the gloves? personally? no. the gloves or the socks, i'll take the gloves. invent a great glove, because that would, i'd buy them very, very quickly. filling our water bucket for boiling. we don't want to go and fall in there because that's a long way down. i reckon it's about —18, —20. sadly, connor didn't manage to capture the northern lights on his night—vision cam but he did take these beautiful pictures on his phone. about 30k to go. perfect conditions. my activity levels, even though i've been trekking for two days solidly, it only gives me 83 out of 100! laughter. thanks for that! it keeps you on your toes, knowing how much sleep you need. it tells you how much rem sleep you had, how much light sleep you had and how much deep sleep you had. and it records, therefore, on the basis of that and the day's activities, the previous day's activities and efforts, how ready you are. when you know you've got that measurement happening all the time, it reminds you to look after yourself and that's the key bit. i've been wearing thermic heated insoles now for a couple of days. the cable coming out the back of the boot gave me horrendous blisters and rubbing. so i cut the cable off and just turned them into normal insoles. this is the snow lizard, fully waterproof, solar powered iphone7 pack. even though your phone is very precious and this one is to me, for sure, you can do that. laughter. connor and tuuka have lost it. and they are diving around in the snow. we still have 21 kilometres to go on day three. oh, my god! how are you doing, john? so far, the crew has been really jolly and talkative. for some reason, there seems to be a little less talking now and the guys are just pushing on. blistered and bloody—toed, we approach the finishing line. cheering. that was the hardest thing i've ever done. we did it. done it. a truly epic challenge. you don't do this to feel warm and comfortable and cosy, actually. you get out to do something like this to raise the money that we have been trying to raise for the lilly foundation but also, for the lily foundation but also, to test ourselves a bit. and tech can take you so far, but ultimately, it's your brain and your endurance and so on that can take you all the way. but i would still like some heated gloves. wow, what a great bunch of guys and what a great story, too, especially considering they filmed that all themselves. the good news is that so far, they've raised over £17,000 for the lily foundation and we wish them and james' daughter, poppy, all the best. for more information on their story and everything else you've seen in this week's programme, check out twitter. we live @bbcclick. thanks for watching. we'll see you soon. good afternoon. easter can be quite unpredictable and that is what we had across scotland, rain, hail, sleet and snow. tonight as those showers clear away and the skies clear it is going to get bitterly cold. i will not be surprised if pla nts cold. i will not be surprised if plants look like this tomorrow. in some places, minus eight degrees. has been dry weather today. the has—been snow in the north—east of scotland. elsewhere there is some sunshine, so there is good weather in the sunshine for the rest of the afternoon and the temperatures will look like this. the cold air will really kick in overnight tonight as the showers move into east anglia and the south—east. cold start in towns and city centres. who'd get as low as minus eight. a hard frost is likely. there will be some decent spells of sunshine tomorrow. if you are extending your easter break her another day there will be a lot of sunshine in the afternoon and highs of 12-14 sunshine in the afternoon and highs of 12—14 degrees. a better day on tuesday than today. it might feel chilly in some places. the odd spot of rainfor chilly in some places. the odd spot of rain for northern ireland and towards the end of the day in the western isles we might see some rain arriving. temperatures little bit disappointing in scotland. a dry story on tuesday. as we move into the middle of the week, it looks like high pressure will stay in the driving seat. the high pressure will hang on and weather france will topple in, introducing more cloud and fleeting showers. 0n topple in, introducing more cloud and fleeting showers. on wednesday the wind direction will change to the wind direction will change to the westerly direction so temperatures will be one degree higher. a dry theme will continue. it will be warm if you get the sunshine by day, but with the clearer skies we're likely to see frost to come. i will be back in half an hour. this is bbc news. the headlines at 3pm: us vice president mike pence warns that his country's "era of strategic patience" with north korea is over. prince harry reveals he's had counselling, to help him come to terms with the death of his mother. i can safely say that losing my mum at the age of 12 and therefore shutting down all of my emotions for the last 20 years has had a quite serious effect on not only my personal life but also my work as well. turkey's president erdogan promises to press ahead with new sweeping powers, after narrowly winning the constitutional referendum. at least 12 people suffer burns after a suspected acid attack at a london nightclub. also in the next hour: should older people be made to retake their driving test? a call for a change in the law that would require all 70—year—old drivers to pass a new test.