but if it's not found until stage four, that falls dramatically to 5%. the trial for this breath test is at the earliest stages, but the team behind it say that, if it works, it could potentially help diagnose other diseases, too. but that's a long way off. catherine burns, bbc news. eight years ago, sally challen, a mother of two, attacked and killed her husband richard with a hammer after 31 years of marriage. she was convicted of murder in 2011. but now, in what's believed to be a legalfirst, she will attempt to have her murder conviction reduced to manslaughter on the grounds that for 30 years she was a victim of her husband's coercive control, a form of extreme psychological abuse. next month, in what will be a landmark case, her lawyers will argue that it was the damage her husband did to her mental state which led her to kill. our home affairs correspondent june kelly reports. on a summer's day in 1979, sally and richard challen were married. she was just 15 when they met. he was her only boyfriend.

their wedding was in surrey, which was where they made their home and raised their family. but throughout their marriage, richard challen was said to have controlled and emotionally abused his wife. in 2010, she killed him. he didn't like her having any independence in terms of friends. it was only friends together. it was a total control. sally challen is now serving life as a convicted murderer. since the killing, coercive control has become a criminal offence. it's domestic abuse which is psychological rather than physical. financial abuse, psychological manipulation... you know, controlling her freedom of movement. just controlling every facet of her mind, and that she would have to answer to him. it was almost like she was a robot and he punched in the commands of what she had to do. richard challen was unfaithful throughout his marriage, visiting brothels and even posing with glamour models

on his christmas cards. in 2009, sally challen finally moved out of the family home and left her husband. but months later, said to be still emotionally dependent on him, she appealed for a reconciliation. richard challen agreed, but with strict conditions. in an e—mail to her, he wrote... "this constant talking to strangers is rude and inconsiderate." and he ordered her to give up smoking and to give up "your constant interruptions when i am speaking". his wife appeared ready to put up with his demands and set off to see him, but in her handbag was a hammer. after she got back here to her old family home, sally challen then went out to buy some food for her husband. but still suspicious of him, when she returned, she began checking his phone, and discovered he'd been in contact with another woman. she cooked him bacon and eggs. and as he ate, she killed him.

she hit richard challen more than 20 times with the hammer, and from the start she admitted her guilt. but despite her appearing to have killed in cold blood, her lawyers will be fighting to have her murder conviction reduced to manslaughter on the grounds that she was suffering from decades of provocation and abuse. nobody is denying that sally challen killed her husband. what is in argument is whether that was murder or whether that was manslaughter. so, there are standard defences for anybody — anybody — who is charged with murder to have that reduced to manslaughter, and one of the things is your state of mind when you did that. what happened in this marriage will be scrutinised in this landmark legal case. june kelly, bbc news. football, and premier league champions manchester city have closed the gap on the league leaders liverpool with a 2—1 win

at the etihad stadium in manchester. 0ur sports editor dan roan was watching the action and is there now. well, liverpool knew that if they could win here this evening, they would open up a nine—point lead at the top of the table and be right on course for a first title for some 29 yea rs. course for a first title for some 29 years. but they knew they were up against the dominant force in the english game in manchester city, the biggest match of the season so far, it's certainly lived up to the billing. manchester city broke all records are to becoming champions last season, but their defence of the title is proving a lot more challenging, and ahead of this — the game of the season so far — it was the visiting fans who arrived full of belief. liverpool, undefeated, and with a six—point lead at the top of the table. much of that's been down to a formidable front three, and one of them, sadio mane, was denied by the post. before confusion reigned in the home defence. city somehow surviving. the goal—line technology showing it had been by the finest of margins.

city were fortunate again that captain vincent kompany didn't see red for this. but what happened next owed nothing to luck — sergio aguero with a finish to match the occasion. the striker continuing his remarkable scoring record against these opponents. with managerjurgen klopp urging his side on after the restart, liverpool's response was emphatic. roberto firmino proving his team's title credentials. but city knew a point wouldn't be good enough. they immediately regained the lead through leroy sane. liverpool had chances to equalise, but ederson kept them at bay. by now the tension spreading to both dugouts. 2—i it finished. liverpool's first league defeat of the season. city showing why they're champions. the title race — wide—open. so, liverpool's lead cut to just four points, city lea pfrogging

so, liverpool's lead cut to just four points, city leapfrogging spurs into second place. liverpool fans will be concerned that tonight's defeat might affect their team's confidence, although it is still very much in their hands. with three teams very much in it, we could be set for a classic title race. that's it from us. here on bbc one, it's time for the news where you are. hello and welcome to sportsday. i'm lizzie greenwood—hughes, here's what's coming up on tonight's show... the premier league title race isn't over yet, as manchester city beat leaders liverpool 2—1 at the etihad tonight. so liverpool are nowjust four points clear at the top, we take a closer look at what this means for the title race. and as michael schumacher turns 50, we reflect on the career of fi's most successful driver, who hasn't been seen in public since a skiiing accident five—years—ago. well it lived—up to its billing...

it was quite a game at the etihad, but we'll have to wait to find out if manchester city's narrow win over liverpool tonight really was the decisive moment of this premier league season. 2—1 the final score. which cuts liverpool's lead at the top of the table now tojust four points. well our correspondent david 0rnstein was following the match at the etihad. david.... well for a match with so much hype.. it didn't disappoint did it? if you think back to the if you think back to the league game at anfield in october, we had

similar hype and that ended up nil nil without out a shot on target until about an hour nil without out a shot on target untilaboutan hourand nil without out a shot on target until about an hour and a game. this had it all for a barely early on in the match. there was a great goal opportunity for liverpool to take the lead, a lead that many would say would be inking with their form the lead, a lead that many would say would be inking with theirform nine with a bounce when said he am on a hit that posed, and managed to clear it just before mohammed hit that posed, and managed to clear itjust before mohammed sele got in. it seemed ii itjust before mohammed sele got in. it seemed 11 mm is the difference between liverpool taking the lead or its things goal is. —— mohammed salah. 0n the other end, manchester city opened the scoring with sergio aguero with a goal that very few other strikers could score. it's that the eddie had —— it said the etihad a while. liverpool would

regroup from half—time, trent alexander arnold voting across the back post, and roberto ever reliable cushioning a simple finish. liverpool bouncing and it seemed like they had the momentum, but champions know how to respond. manchester city going of the other end raheem sterling with a beautiful assist, and that would work coming to city's recchi and for the second time in the match. —— city's rescue per the second time in the match. it's a huge win for manchester city, and for the title race here in england as well. of course this wasn'tjust about of course this wasn't just about two teams play each other, regardless all of us wanted to see manchester city and liveable again this season, but this of course was about that

race, just for voice now. what has been the reaction there? —— see manchester city and liverpool play again this season... of course this opportunity feeds this season to crystal palace while liverpool charged in the title race and overtook them for that no team has turned the year with such a point advantage and failed to win the title, however liverpool had a reality check tonight. they are bored points clear so let's hear from both of the management now. we are not scared, we know what no matter what happened we had lots of pressure today because it would have been almost out for the fight for the premier league, because their leaders there still four points ahead. a very intense game. a very

difficult game for both sides. sitting at the post of the ball goes m, sitting at the post of the ball goes in, and that went out or it nearly we nt in, and that went out or it nearly went and that's how it is. it's not easy to take them to the end. it's probably a score score one. we had out probably a score score one. we had our chances so it's just probably a score score one. we had our chances so it'sjust an outstanding game. two teams at the fight like crazy. well, that city we re fight like crazy. well, that city were never going to give up their crown without a fight, and all liverpool remain top of the table, the title race really has now been blown wide open in what is shaping up blown wide open in what is shaping up to bea blown wide open in what is shaping up to be a thrilling premier league season. well let's see where this leaves liverpool and the premier league title race, joe lynsky is at the touch—screen, it feels like the season just got a bit longer for liverpool. and liverpool is going to win their

first title in 29 years it seemed like the season just got longer. that gap we were saying before they could have been ten points but as it is it's just poor, could have been ten points but as it is it'sjust poor, and could have been ten points but as it is it's just poor, and you could have been ten points but as it is it'sjust poor, and you can could have been ten points but as it is it's just poor, and you can see just as well, the spurs have benefited from just a congested the top three is there six points behind. let's have a look at some of those incidents this evening because we saw in the report there how close back the ball was to going over the line for this opening goal for liverpool was that —— for liverpool. sergio aguero was who put manchester city in front, and liverpool fans saw him score right in front of them to build be sick of the sight of him because aguero has now scored in every home game against liverpool,

seven games since he joined manchester city. as it was though it was leroy got the winning goal in the game. he has been involved in 26 goals and 25 home but are merely games. —— home per merely games. liverpool has conceded a goal this season and this is the ist of may have conceded two goals in a game since playing wes brown last april. and you can see that breached liverpool's extraordinary defensive record this season. the first time they've conceded two goals in a game since playing west brom in april. so this is what's next for these teams, and actually liverpool will be pretty confident of building some momentum again with this run of fixtures. they go to brighton next while city will have eyes on keeping tonight's momentum going up to those two home games against arsenal and chelsea. michael schumacher turns 50 today. but formula one's most successful driver hasn't been seen in public

since his skiiing accident 5—years—ago and still little is known about his condition. ben croucher reflects on the 7 time world champion's career. notjust not just anybody could notjust anybody could defy not just anybody could defy their error, but michael schumacher is not just anybody. —— defined and their era. the most successful formula i driver turns 50 today. a record era. the most successful formula 1 driver turns 50 today. a record 71 titles, 91 race wins, and jaw—dropping brilliant spotting over the master and the weight of times, that insatiable will to be first to cross the line often across the line. he was destined for greatness from his first race withjordan in 1991, gary anderson recalls fondly. he expected to be great at things but you never know what it's going to grow up to be, as far thought was concerned we new you is potentially

very quick. then in december 2013 not long after retiring, tragedy struck. good evening the former world racer michael schumacher isn't mental conditioning —— is in critical condition in the hospital.