Blake Adam Austin, 35, pleaded guilty on Tuesday to cyberstalking and distributing child pornography, U.S Attorney Stephen McAllister said.
The Topeka man had been using a middle school teacher’s identity to post sexual content and her contact information for a number of years.
Investigators learned Austin also used images of the victim to place half a dozen ads on Craigslist.
The victim had previously known Austin when they worked together at a coffee shop, where he had attempted to pursue a relationship with her, but she had not been interested.
On his laptop Austin had explicit photos of underage girls, which he had also uploaded to Skype.
His sentencing is set for Aug. 20.
He faces a penalty of up to five years in federal prison on the cyberstalking charge, up to 10 years on the possession charge and not less than five years on the distribution charge.