According to The Smoking Gun's website, they have received some interesting information via a hacker who calls themselves, Guccifer 2.0. This person claims to be a Romanian hacktivist. There is another hacker who is named Guccifer [Marcel Lazăr Lehel], who is currently in jail in Alexandria, VA. He has not gone missing, nor is he dead, as some "news publications" are currently claiming.
The investigation concluded this breach to be coming from Russian espionage. On Guccifer 2.0's website, they have released documents showing plans to be carried out during the Republican National Convention.