Washington (CNN) — A federal grand jury in Washington, DC, on Friday approved the first charges in the investigation led by special counsel Robert Mueller, according to sources briefed on the matter. The charges are still sealed under orders from a federal judge. Plans were prepared Friday for anyone charged to be taken into custody as soon as Monday, the sources said. It is unclear what the charges are. A spokesman for the special counsel's office declined to comment. Mueller was appointed in May to lead the investigation into Russian meddling in the 2016 election. Under the regulations governing special...