It was confirmed on Friday by the FBI that an IRS agent was shot and killed in a routine firearms training. The shooting occurred on Thursday at the firing range of the Phoenix federal prison, which also happens to be an interagency training ground for federal agents in the Phoenix region.

Special agent Patrick Bauer, 47, was fatally wounded. He was a retired master sergeant in the Arizona National Guard. The nature of the exercise is currently unknown.

The only statement issued by the IRS Criminal Investigation was made on Twitter where their post reads, “It is with great sadness we announce the End of Watch for Special Agent Pat Bauer. We honor his service to the nation, both as a federal law enforcement officer and as a retired master sergeant in the Arizona National Guard.”

Officials with the FBI’s Phoenix field office said they will oversee the shooting investigation. The findings will be turned over to the U.S. Attorney’s Office for the District of Arizona.