MADISON, Wis. -

Gov. Scott Walker said he is frustrated that a registered sex offender who stood next to him during the State of the State speech was not caught during a background check.

Walker reacted Thursday to the news that welder Christopher Barber is a registered sex offender with two felonies and three drunken-driving offenses.

"Well obviously it's frustrating. There's no way if we'd known that he'd be on. Of all those people out there, all of them have background checks. This particular individual was one of the last people added. It came from a credible employer who gave us the suggestion at the last minute," Walker said.

Barber was one of several workers Walker introduced during his speech to illustrate an improving state economy.

Barber was hired by Ariens Co. in Brillion in late 2012. He wore his welding helmet and work gloves on stage with Walker during the speech.

Online court records show Barber has been in and out of jail for much of the past 10 years.

Walker said he assumed a background check had been done, but it had not.