Going to shoot Obama from a high vantage point using ... a rifle ... sighted at 750 yards (metres)

A Denver-based CBS television station reported the man, one of three arrested by authorities, said they were "going to shoot Obama from a high vantage point using ... a rifle ... sighted at 750 yards (metres)".FBI is investigating whether a man arrested in Denver with rifles, ammunition and drugs in his pick-up truck has made threats against Democratic White House hopeful Barack Obama.The shooting was supposed to happen on Friday (AEST) when Obama will accept the nomination as the Democratic Party's presidential candidate for the November election, the television station reported."It's premature to say that it was a valid threat or that these folks have the ability to carry it out," said one US government official familiar with the investigation.FBI spokeswoman Kathy Wright confirmed the FBI was investigating the reports but declined to elaborate.Tharin Gartrell, 28, was arrested during a traffic stop early Sunday by police in the eastern Denver suburb of Aurora.In his truck, officers found two rifles, including one with a scope; a bulletproof vest; boxes of ammunition; walkie-talkies; and suspected narcotics, said Aurora police Detective Marcus Dudley.Police alerted federal authorities, who soon arrested Nathan Johnson, 32, at a hotel in Denver, Dudley said. A third man, Shawn Robert Adolf, 33, was arrested at a suburban Glendale hotel, Dudley said.Adolf allegedly tried to escape from officers by jumping from a sixth-floor window. He was hospitalised and was being held on $US1 million ($A1.2 million) bond for several outstanding warrants involving drug charges.Johnson also was being held on drug charges and his bond was unknown, Dudley said.Dudley didn't say what tied the men together but that more arrests were possible. One of the rifles was stolen, and authorities had traced it to Kansas, Dudley said. He declined to say to whom it belonged.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," he said.
"The weapons clearly would cause great concern."US 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 statement.Officials with the FBI, Secret Service, Bureau of Alcohol, Tobacco, Firearms and Explosives, and Aurora police have announced a news conference for Tuesday.Authorities in Denver are trying to find out whether the reported threats to Obama were valid.
"It could also turn out that these were nothing but a bunch of knuckleheads, meth-heads," one US government official said.