SPRINGFIELD, Mo. – A man from Springfield admitted to bringing a cell phone- with child sex abuse material- into a secure government facility.

Shaun Walker pleaded guilty to the federal charges today. Prosecutors say he was working for a company the Nuclear National Security Administration contracted at the time.

His phone was searched for classified material after he entered the facility. That’s when the images were found and his phone was seized. Investigators later found a hidden folder with more images.