A Utah man pleaded guilty Monday to threatening U.S. Anti-Doping Agency CEO Travis Tygart after the organization decided to strip bicycle race champ Lance Armstrong of his Tour de France titles.

Robert Hutchins, 60, of Sandy, Utah, sent two e-mails expressing his frustration to Tygart, who heads the agency located in Colorado Springs, in which he didn't make any threats.

But after Armstrong released a statement last Aug. 23, saying he wouldn't challenge the agency's findings, Hutchins crossed a line, said Assistant U.S. Attorney Valeria Spencer.

"I hope you have body guards and a bullet-proof vest, you are a dead man," Hutchins wrote, Spencer said at the hearing in U.S. District Court in Denver.

He later told investigators he was just blowing off steam.

Read more here.