A Utah man was shot and killed during an FBI raid early Wednesday morning, the FBI confirmed to ABC News. The raid was in connection with an investigation into alleged threats against President Joe Biden and others, according to two officials briefed on the case.

One of the officials told ABC News that the investigation began in April and the U.S. Secret Service was notified by the FBI in June. In addition to threatening posts, the official said, the man under investigation suggested online he was making plans to take physical action. The threats had been deemed "credible," the official said.

The FBI in Salt Lake City said the shooting occurred around 6:15 am. local time while special agents attempted to serve arrest and search warrants at a residence in Provo.

"The FBI takes all shooting incidents involving our agents or task force members seriously," the FBI said in a statement. "In accordance with FBI policy, the shooting incident is under review by the FBI's Inspection Division. As this is an ongoing matter, we have no further details to provide."

The deceased suspect was Craig Robertson, according to multiple sources and a federal complaint obtained by ABC News.

Robertson was facing three counts, according to the complaint -- interstate threats, threats against the president, and influencing, impeding and retaliating against federal law enforcement officers by threat.

The complaint includes numerous social media posts believed to have been made by Robertson threatening to kill Biden and Vice President Kamala Harris, as well as several officials involved in prosecuting former President Donald Trump.

The president is scheduled to visit Utah on Wednesday.

Among the posts allegedly made by Robertson was one published on Aug. 6, three days before Biden's scheduled visit, according to the complaint. "I hear Biden is coming to Utah. Digging out my old ghillie suit and cleaning the dust off the M24 sniper rifle," the post said, according to the complaint, which referred to the post as a "willful true threat to kill or cause injury to kill President Biden."

Senior staff briefed Biden on the incident Wednesday morning, a White House official told ABC News.