A 25-year-old Columbia college student has been arrested after federal agents said they discovered he had fraudulently obtained dozens of firearms and more than 23,000 rounds of ammunition. The man, federal prosecutors said on Wednesday, had also researched mass shootings on his computer. Edward Daniel Kimpton Jr. has been charged with federal wire fraud, mail fraud and possession of machine gun violations. In a complaint filed by the Bureau of Alcohol, Tobacco, Firearms and Explosives, agents said Kimpton, a student at Midlands Technical College, had used a complicated scheme to obtain weapons, ammunition and tactical gear without paying for them....