Hibbard's ex-wife, Rashell Langford, died last September when she shot herself while ingesting drugs known as "bath salts" and drinking alcohol with her husband, according to police.
Shawn Langford, charged with misdemeanor negligent homicide, pleaded guilty last week to an alternate misdemeanor count of reckless endangerment for backing out of a suicide pact the couple made. He faces up to a year in jail when he is sentenced Nov. 5.
Hibbard, however, told a Tribune reporter he was convinced the investigation into his wife's death was botched believing Shawn Langford should have been charged with murder. Hibbard also contacted Gill.
"I met with Mr. Hibbard about a month ago and sat with him for a couple of hours ... listened to his concerns," Gill said Wednesday. "He was a little agitated."
Gill declined to say whether Hibbard said anything about the Langford case at the FBI office, but Hibbard did mention the agency to The Tribune in long phone messages he left, which became increasingly agitated over the ensuing weeks.
On Monday, Hibbard was on the 6th floor of the FBI building when he grabbed a 61-year-old man who worked in a separate office at the 257 Tower Building at 257 East 200 South.
Hibbard told the hostage that he needed a forensic psychiatrist and that the FBI had one, according to charges.
He put an object to the victim's back and stated, "This is a hostage situation," according to charges. He also said that he had a gun.
Hibbard forced the man into an elevator and pushed the button for the 12th floor, where the FBI offices are.
When they arrived on the 12th floor, Hibbard loosened his grip on the victim and handed him the knife he had been holding to his back, according to charges.
An FBI agent took Hibbard into custody.
Meanwhile, a witness had called 911, and Salt Lake City police quickly rushed to the scene.
The hostage was unharmed.
Hibbard, listed as a Nevada native, was booked into Salt Lake County jail.
He has been charged with one count of first-degree felony aggravated kidnapping.
His first court appearance is set for Monday before Judge Elizabeth Hruby-Mills. Bail has been set at $1 million.
The Utah Department of Corrections has confirmed that Hibbard was discharged in May 2010 from supervised probation for previous sexual battery and attempted theft by receiving stolen property convictions. Corrections spokesman Stephen Gehrke said Hibbard was being supervised in Utah as part of a probation monitoring agreement with another, unspecified state.
A search of Utah court records shows Hibbard has a criminal record beginning in 1991 that includes misdemeanor convictions for possession of a controlled substance, retail theft, simple assault and forcible sexual abuse.