Lloyd of Follansbee, West Virginia, was also allegedly responsible for stickers placed in predominantly Jewish areas of Pittsburgh directing people to a website containing his threats and antisemitic messages.
Lloyd faces charges of obstruction of the due administration of justice, transmitting threats in interstate and foreign commerce, and witness tampering.
The charges carry a total maximum punishment of 35 years in prison if convicted.
In May last year, the Texas Department of Public Safety offered a cash reward of up to $1,000 for information leading to Lloyd's arrest after he allegedly posted a series of comments online threatening to carry a firearm onto the Texas State Capitol grounds and challenge any police officer who tried to "take enforcement actions" against him.
A statement from the department said Lloyd was a convicted criminal.
US Attorney William Ihlenfeld said: “Jury trials are a hallmark of the American justice system and attempts to intimidate witnesses or jurors will be met with a strong response.
“The use of hateful threats in an effort to undermine a trial is especially troubling."
The Justice Department described Lloyd as a self-proclaimed "reverend" of a white supremacy movement.
