Washington (CNN) -- Are James V. McVay's statements the shocking confessions of a man who planned to kill the president? The exaggerated claims of someone seeking attention? The rantings of a lunatic? Police, prosecutors and others are asking those questions after McVay, 41, was charged in the vicious stabbing death of a 75-year-old woman in Sioux Falls, South Dakota. Stopped by police Saturday near Madison, Wisconsin, some 450 miles away from the killing, McVay confessed not only to the stabbing, but to a crime he said he hoped to commit: the assassination of a president. In statements to police, and in an unusual jailhouse interview with reporters, McVay said: --

He had spent two years while in prison developing a plan. -- He planned, first, to kill someone in Sioux Falls and steal that person's vehicle to drive to Madison. -- In Madison, he would break into another house to kill the occupants and steal their vehicle, or he would ambush a Madison police officer to steal that officer's gun. -- He planned to travel through Chicago, stopping again in Indianapolis to kill people and steal a vehicle to drive to Washington. "I'm going to kill and kill until I get him," he told police, referring to President Obama. "One of his favorite pastimes, golfing; I was going to get him at the golf range," McVay said in a remorseless interview with WKOW-TV reporter Tony Galli. He said the Sioux Falls victim, Maybelle Fetters Schein, was "collateral damage."