“We’ve got someone worse than the Gravedigger coming,” Bones creator Hart Hanson told me over the summer. “And if the Gravedigger is Evil Brennan, this [guy] is Evil Booth. Remember, Booth was a sniper.”
Vosloo — who also played the title role in the Darkman films as well as Brendan Fraser’s nemesis in The Mummy and The Mummy Returns — is slated to appear in at least three episodes beginning in early ’11.

Source: EW