SALT LAKE CITY -- Police are investigating why a knife-wielding man took a worker hostage in the elevator of a downtown Salt Lake City building that houses FBI offices.
Robert Joseph Hibbard, 41, was moving from floor to floor Monday afternoon in the building at 257 E. 200 South and holding a man against his will at knife-point, police said.
Hibbard was detained by agents as he stepped off the elevator into the lobby of the FBI offices on the 12th floor.
The 61-year-old victim, who works in the building, was unharmed.
The Salt Lake Tribune reports Hibbard did not resist arrest and was booked on suspicion of aggravated kidnapping.
KTVX-TV reports police have not determined a motive for the hostage taking or whether it was targeted to the FBI.
FBI spokeswoman Deborah Bertram told the Tribune on Tuesday that she could not comment on the incident and discuss a possible motive or whether there were any connections to the FBI.
The case has been turned over to Salt Lake Police, Bertram said.
Statements that Hibbard made to officers after he was arrested did not provide any insight into a possible motive, said police Sgt. Shawn Josephson.
"We don't have a clear indication why he picked that building or why he then went to the FBI offices," Josephson said. "There's no indication he knew the victim or that he had a particular beef with the government."
Hibbard is listed as a Nevada native, the newspaper reported.
In May 2010, he was released from supervised probation for sexual battery and attempted theft. Hibbard was in Utah under a probation monitoring agreement with another state, said Utah Department of Corrections spokesman Stephen Gehrke.