The man being held in connection with the death of MP Jo Cox has been named as Thomas Mair, who was described as a “loner” with a history of mental health problems who had previously subscribed to a far-right magazine. 
 
 Mair, 52, who was arrested by armed officers shortly after the attack, had spoken about receiving “psychotherapy and medication”, and was described by his younger brother as having “a history of mental illness”. 
 
 Despite being born in Kilmarnock, Scotland, a decade-old website posting identified Mair as a subscriber to S. A. Patriot, a South African magazine that was published by the pro-apartheid group, the White Rhino Club. ||||| Tributes are taking place throughout Britain for lawmaker Jo Cox, who was shot and stabbed in a daylight attack in a small town in the north of England on Thursday. (AP) 
 
 Tributes are taking place throughout Britain for lawmaker Jo Cox, who was shot and stabbed in a daylight attack in a small town in the north of England on Thursday. (AP) 
 
 The killing of a promising young British lawmaker who advocated passionately for refugees spawned a national reckoning Friday over a political culture that has turned increasingly intolerant in the final days of a bitter campaign to determine whether the country leaves the European Union. 
 
 The soul-searching spawned by the death of 41-year-old Jo Cox has the potential to reset the tone of the E.U. debate and could influence its outcome when the country votes Thursday. 
 
 Any overt campaigning has been put aside until Sunday as the nation continues to mourn Cox, who died Thursday afternoon after being stabbed and shot outside the library in this quiet northern English market town. 
 
 But revelations that the alleged perpetrator had long-standing affiliations with neo-Nazi and other far-right groups prompted a widespread demand Friday for an end to the divisive rhetoric that has marred the referendum campaign. 
 
 In a rare joint appearance, British Prime Minister David Cameron and Labour Party leader Jeremy Corbyn visited the makeshift memorial set up near the site where Cox was killed. Both called for a kinder and less poisonous brand of politics. 
 
 Witnesses told British media that the assailant appeared to have been waiting for Cox outside a library in the town of Birstall, where she had been meeting constituents. (TWP) 
 
 “Where we see hatred, where we find division, where we see intolerance, we must drive it out of our politics and out of our public life and out of our communities,” Cameron said. 
 
 Corbyn blamed the killing on “a well of hatred” and described it as “an attack on democracy.” 
 
 [What the fatal attack on a British politician says about guns in Britain] 
 
 Much of the E.U. referendum campaign has been dominated by anxiety over immigration, with supporters of an exit arguing that Britain risks being overrun by newcomers if it does not leave the 28-member bloc and erect higher barriers to entry. 
 
 Police said Friday they are still investigating what led the killer to attack Cox. But witnesses at the scene reported that a man appeared to have been waiting for her outside the library, and that he shouted “Britain first!” during and after the assault. The man was arrested as Cox lay dying on the sidewalk. 
 
 Dee Collins, the temporary chief constable of the West Yorkshire Police, said in a statement Friday evening that possible links to right-wing extremism were a “priority line of enquiry” in the investigation. She said the alleged perpetrator’s mental health was also being examined. 
 
 Early on Saturday, police announced charges of murder against 52-year Thomas Mair, a longtime resident of Birstall. 
 
 1 of 29 Full Screen Autoplay Close Skip Ad × United Kingdom pays tribute to slain British lawmaker Jo Cox View Photos Cox, a member of Britain’s Parliament, was shot and stabbed near the northern city of Leeds. Caption Cox, a member of Britain’s Parliament, was shot and stabbed near the northern city of Leeds. June 17, 2016 Candles surround a photo of British lawmaker Jo Cox before a vigil in her memory at George Square in Glasgow, Scotland. In the foreground, Scottish Labour Party leader Kezia Dugdale holds a rose. Jeff J. Mitchell/Getty Images Buy Photo Wait 1 second to continue. 
 
 The British media has reported that neighbors and family members have described Mair as quiet and seemingly apolitical. 
 
 But according to documents obtained by the Southern Poverty Law Center, a U.S.-based organization that tracks extremist groups, Mair was a longtime supporter of the National Alliance, a once-prominent white-supremacist group. In 1999, Mair bought a manual from the organization that included instructions on how to build a pistol, the center said. 
 
 [Husband of slain British lawmaker vows to ‘fight against the hate’ that killed her] 
 
 Cox was shot with a weapon that witnesses described as either homemade or antique, though the BBC reported Friday that police did not think the weapon had been assembled by Mair. 
 
 In all, Mair sent $620 to the National Alliance’s publishing arm for titles including “Incendiaries,” “Chemistry of Powder and Explosives,” “Improvised Munitions Handbook” and “Ich Kampfe,” published by the World War II-era Nazi party, the law center said. 
 
 Various British media outlets also reported that Mair had subscribed to a South African magazine published by the White Rhino Club, a pro-apartheid group. 
 
 Nick Lowles, chief executive of the British-based anti-extremist group Hope Not Hate, said Mair had an affiliation with far-right groups that stretched back decades, although he was not a prominent player in any of them. 
 
 [Jo Cox, slain British politician, was a champion of refugees] 
 
 “It fits a pattern of far-right attacks. We’ve had a number of these lone wolves — men in their 50s who are on the periphery of these movements and who believe that the battle is coming,” he said. “On the one hand, they’re on their own. But they’ve also been inspired by a lot of the things they read.” 
 
 It remains unclear whether the attack had any links to debates over immigration ahead of the E.U. vote next Thursday, Lowles said. But he described the current atmosphere as “increasingly toxic.” 
 
 “That leads to increased prejudice. That leads to increased hate. And, at some stage, that leads to violence,” he said. “Whatever the outcome next week, the U.K. has become a much more intolerant and divided society. It’s going to take a long time to heal.” 
 
 On the day of the shooting, Nigel Farage, the leader of the anti-immigration U.K. Independence Party, unveiled a referendum campaign poster showing a massive line of migrants and refugees along with the slogan: “Breaking Point. We must break free from the E.U. and take control of our borders.” 
 
 Nicola Sturgeon, the first minister of Scotland, called the ad “disgusting.” 
 
 [A British vote to leave the E.U. could shatter the United Kingdom] 
 
 “When you shout ‘breaking point’ over and over again, you don’t get to be surprised when someone breaks,” said the Spectator magazine’s Alex Massie. “When you present politics as a matter of life and death, as a question of national survival, don’t be surprised if someone takes you at your word. You didn’t make them do it, no, but you didn’t do much to stop it, either.” 
 
 With flags flying at half-staff outside 10 Downing Street and Buckingham Palace, both sides in the E.U. referendum debate said they would hold off on any major campaign activity until Sunday. Recent polls have shown the campaign is effectively tied, with “out” perhaps holding a slight advantage. 
 
 Security will be a concern when campaigning resumes, a rarity in British politics. Collins, the police official, said authorities think the assault on Cox was “a single isolated attack.” But threats against members of Parliament have been rising in recent weeks. 
 
 Anna Turley, a Labour lawmaker, told the BBC that she and Cox talked often about the “increasing nature of hostility and aggression, particularly towards female [members of Parliament], particularly on social media.” Turley added, “We were all reviewing our security.” 
 
 But she insisted that “Jo would not have wanted us to be hidden and be behind walls.” 
 
 Before Cox won election to Parliament last year, the mother of two had a career in humanitarian work, including for the aid organization Oxfam. She was a strong advocate for an inclusive and multicultural Britain, and she pushed for the country to take in thousands of child refugees. 
 
 People who knew her — and those who did not — placed flowers at the foot of a statue in Birstall’s central square throughout the day Friday. Also left in tribute: heartfelt letters, poems and cards expressing sorrow and disbelief. 
 
 [British government could also hang in balance of E.U. referendum] 
 
 The visitors reflected the diversity of the community. White Britons, Eastern European immigrants and members of the area’s long-standing South Asian community gathered to pay respects. 
 
 “She was genuine, caring. A proper Yorkshire lass,” said Nazir Daud, 41. “She wasn’t one of those politicians who just tries to make her name. She genuinely worked hard for the community.” 
 
 Daud said Cox never failed to return his calls or text messages relaying concerns among worshipers at his mosque. He scrolled through a stream of text exchanges to find the last: a message from Cox wishing him a happy Ramadan. 
 
 “She stood for a multicultural vision of Britain,” he said. “She was always fighting for justice and equality.” 
 
 And that, Daud said, was also why she was killed. 
 
 Adam reported from London. 
 
 Read more: 
 
 What would Britain look like post-Brexit? Here are four possibilities. 
 
 Anti-Muslim group picks a fight in British Muslim neighborhood, and gets one 
 
 As polls tighten, Cameron pleads with unhappy voters to back away from ‘Brexit’ 
 
 When Britain votes on the E.U., Western security could be on the line 
 
 Post correspondents around the world ||||| Jo Cox, a member of the Labour Party in the British Parliament, died Thursday after an attack by a lone man who shot and stabbed her in West Yorkshire following a regular public meeting she held with constituents. 
 
 
 
 Jo Cox (AP Images/Yui Mok/PA) 
 
 Her alleged killer is Thomas Mair, 52. According to eyewitness accounts, which are still under investigation, Mair was armed with a knife and a gun, either antique or homemade, and may have shouted “Britain First” when he attacked Cox, a possible reference to the far right Britain First party, whose leader, Paul Golding, is a former member of the white nationalist British National Party. The Daily Telegraph reported that Mair’s brother claimed Mair has a “history of mental illness,” and neighbors called him a “loner,” but he also has a long history with white nationalism. 
 
 According to records obtained by the Southern Poverty Law Center Mair was for decades a dedicated supporter of the National Alliance (NA), the once premier neo-Nazi organization in the United States. Mair purchased a manual from the NA in 1999 that included instructions on how to build a pistol. 
 
 Mair, who resides in what is described as a semi-detached house on the Fieldhead Estate in Birstall, sent just over $620 to the NA, according to invoices for goods purchased from National Vanguard Books, the NA’s publishing imprint. Mair purchased subscriptions for periodicals published by the imprint, and he bought works that instruct readers on the “Chemistry of Powder & Explosives,” “Incendiaries,” and a work called “Improvised Munitions Handbook." Under “Section III, No. 9” (page 125) of that handbook, there are detailed instructions for constructing a “Pipe Pistol For .38 Caliber Ammunition” from components that can be purchased from nearly any hardware store. 
 
 The NA may be best-known for the work of its now-deceased founder, William Pierce, a former physics professor who also wrote racist novels. One, The Turner Diaries, tells the post-apocalyptic fictional story of a white man fighting in a race war that may have provided inspiration for Oklahoma City bomber Timothy McVeigh. 
 
 The Daily Telegraph also reported that Mair was a subscriber to S. A. Patriot, a South African magazine published by White Rhino Club, a pro-apartheid group. The club describes that magazine’s editorial stance as opposed to “multi-cultural societies” and “expansionist Islam.” According to the Daily Telegraph, a January 2006 blog post attributed to the group described Mair as “one of the earliest subscribers and supporters of S. A. Patriot.” 
 
 
 
 Thomas Mair 
 
 Cox, 41, known as a rising star in the Labour Party, was an advocate for Syrian refugees. She had worked as an aid worker in developing countries and went on to become head of policy at Oxfam. She had also worked as an advisor to Sarah Brown, wife of the former Labour Prime Minister Gordon Brown, in women’s and children’s health campaigns. Cox was elected to Parliament in 2015 and quickly gained a reputation for taking on her own party’s leadership. She supported staying in the European Union in the face of the upcoming so-called “Brexit” referendum, which will determine whether the UK leaves the European Union. 
 
 
 
 The "Improvised Munitions Handbook" is among the books purchased by Mair from the National Alliance, which includes these instructions for building a homemade gun. 
 
 
 
 Order Mair made in May of 1999 from National Vanguard Books. Includes handbooks titled "Chemistry of Powder & Explosives" and "Improvised Munitions Handbook."
– The man accused of Thursday's shocking murder of a British lawmaker in broad daylight appears to have connections to a white supremacy group in the US. The Southern Poverty Law Center reports that Thomas Mair, 52, in 1999 spent $620 on how-to manuals about guns and explosives from a neo-Nazi group called the National Alliance, including one about building a homemade pistol. Along those lines, the Telegraph reports that Mair was a subscriber to a pro-apartheid magazine in South Africa, with a 2006 blog attributed to the magazine's publisher describing him as "one of the earliest subscribers and supporters of S. A. Patriot.” Police have yet to speculate about a motive for the slaying of 41-year-old Jo Cox, who was a strong advocate for more inclusive immigration policies in Britain, especially for Syrian refugees. Witnesses have said that Cox's killer yelled "Britain first!," which also happens to be the name of a far-right British group known for its anti-Muslim demonstrations, notes the Washington Post. The group has disavowed the slaying. Cox's murder also comes just a week ahead of the UK referendum on whether to leave the European Union, a vote in which the issues of immigration and national identity have been huge factors, reports the New York Times. Campaigning on the so-called Brexit vote was temporarily halted by both sides in the wake of her death. Mair's brother, meanwhile, says he's stunned. "My brother is not violent and is not all that political," he says. "I don’t even know who he votes for. He has a history of mental illness, but he has had help.”