A Collin County detention officer has been charged with possession and promotion of child pornography.
The National Center for Missing and Exploited Children sent a cyber tip to local police about graphic images of child pornography getting uploaded in the area.
An address was traced to the Parker home of Keith Michael Duncan.
Duncan has been a detention officer in Collin County since 2008 and is now an inmate at the jail he guarded.
"It's very surprising and very disturbing," said Lt. John Norton. "We're very disappointed."
The search warrant said the computer was owned by Duncan. There were at least 40 photos of girls as young as 4 years old being abused and sexually assaulted by adults, according to the warrant.
Authorities are trying to determine if any of the children photographed are local and if Duncan ever used county equipment to access child pornography.
"We'll look into it," said Norton. "It's very highly unlikely we have nothing to indicate the he's done anything while on duty or with county equipment."
Duncan's wife told NBC 5 that she was shocked, saddened and sickened by the accusations.
NBC 5's Randy McIIwain contributed to this report.