A special counsel to investigate charges against Hunter Biden, son of President Joe Biden has been appointed. Attorney General Merrick Garland said Delaware U.S. Attorney David Weiss requested special counsel status this week as the investigation continues.

Calls for a special counsel grew after a plea agreement between Biden and federal prosecutors fell apart in court as he was set to plead guilty. The deal would have settled tax evasion and gun charges that Hunter is facing.

Republicans have accused the Justice Department of giving Hunter preferential treatment in the case by offering him a “sweetheart deal.”