DENVER (CBS) ― CBS Station KCNC in Denver has learned at least four people are under arrest in connection with a possible plot to kill Barack Obama at his Thursday night acceptance speech in Denver. All are being held on either drug or weapons charges.
KCNC Investigator Brian Maass reported one of the suspects told authorities they were "going to shoot Obama from a high vantage point using a ... rifle … sighted at 750 yards."
Law enforcement sources said that one of the suspects "was directly asked if they had come to Denver to kill Obama. He responded in the affirmative."
The story began emerging Sunday morning when Aurora police arrested 28-year-old Tharin Gartrell. He was driving a rented pickup truck in an erratic manner according to sources.
Sources told KCNC that police found two high-powered, scoped rifles in the car along with camouflage clothing, walkie-talkies, wigs, a bulletproof vest, a spotting scope, licenses in the names of other people and 44 grams of methamphetamine. One of the rifles is listed as stolen from Kansas.
Aurora police alerted federal officials because of heightened security surrounding the Democratic convention, Dudley said.
"Clearly we found there are federal implications -- otherwise we would not have notified them," Det. Marcus Dudley with Aurora police said. "The weapons clearly would cause great concern."
Subsequently authorities went to the Cherry Creek Hotel to contact an associate of Gartrell's. But that man, identified as Shawn Robert Adolph, 33, who was wanted on numerous warrants, jumped out of a sixth floor hotel window. Law enforcement sources say Adolph broke an ankle in the fall and was captured moments later. Sources say he had a handcuff ring and was wearing a swastika, and is thought to have ties to white supremacist organizations.
A third man -- an associate of Gartrell and Adolph, Nathan Johnson, 32, was also arrested. He told authorities that the two men "planned to kill Barack Obama at his acceptance speech."
Johnson, along with his girlfriend, Natasha Gromek, are also under arrest on drug charges.
The Secret Service, FBI, ATF and the joint terrorism task force are all investigating the alleged plot.
The U.S. Attorneys Office has scheduled a news conference for Tuesday afternoon. The U.S. Attorney in Denver said it does not believe there is a credible threat to Obama or the convention.
"It's premature to say that it was a valid threat or that these folks have the ability to carry it out," said a U.S. government official familiar with the investigation. The official spoke on condition of anonymity because the investigation is ongoing.
U.S. Attorney Troy Eid said the case was under investigation.
"We're absolutely confident there is no credible threat to the candidate, the Democratic National Convention, or the people of Colorado," Eid said in a prepared statement.