DENVER -- Four people suspected of being involved in a plan to assassinate Barack Obama are currently being held in Denver city jail.

The U.S. attorney for Colorado, who'll be holding a press conference to discuss this later today, said in a statement released Monday night, "We're absolutely confident there is no credible threat to the candidate, the Democratic National Convention, or the people of Colorado." And another unnamed "U.S. government official familiar with the investigation" told CBS4, the local CBS affiliate, that "it's premature to say that it was a valid threat or that these folks have the ability to carry it out."

However, the alleged plot was uncovered during a routine traffic stop that turned up, according to the Denver Post, "two rifles ... a high-powered scope, a bulletproof vest, a walkie-talkie, several boxes of ammunition and some methamphetamine." And according to CBS4, one of the suspects has told law enforcement that the group was "going to shoot Obama from a high vantage point using a ... rifle ... sighted at 750 yards." CBS4 also says that, according to authorities, one of the suspects "was directly asked if they had come to Denver to kill Obama. He responded in the affirmative."

CBS4 also scored a major scoop with an interview of Nathan Johnson, one of the suspects. Asked, "Do you think they were really plotting to kill Obama?" Johnson replied, "I don't want to say yes. I don't want to say no."

Another of the suspects, Shawn Robert Adolf, who was wanted on multiple warrants, jumped out of a sixth-floor window and broke his ankle when police went to his hotel. He was reportedly wearing a swastika ring at the time, and is alleged to have connections to white supremacist groups.