MILTON -- Photographs of young boys urinating and videos of them having sex with one another were among the child pornography files found in January on a laptop computer owned by a Sunbury man, a Milton police detective testified Thursday.

During a preliminary hearing, District Judge William F. Kear bound charges against Thomas A. Dreistadt to Northumberland County court, and defense attorney Peter Campana had to turn away several times from a computer showing the images.

Charges against Dreistadt include nine counts of felony sexual abuse of children and nine counts of felony possession of child pornography.

A computer owned by Dreistadt, 21, and kept at times at the Milton Fire Department, had nine videos and nine pictures depicting child pornography, said trooper Thomas Trusal, a computer investigator with state police at Selinsgrove.

During an investigation on Dreistadt's computer in January, Trusal said he found thousands of files on Dreistadt's computer. His report listed four to five pages of file names, titled "pre-teen boys," "pthc" or preteen hard core, and "twosweetboys7yo," standing for 7 years of age.

Only 18 remained on the computer in January.

Trusal, who said he has been examining computers since 1999, said Milton police detective Todd Ulrich gave him the computer and made a forensic copy of the hard drive. Trusal then discovered the nine video clips and 10 photos of young boys unclothed.

However, investigators were unable to determine the age of a boy in one photograph that showed only his genitals.

The pictures were all of young boys urinating with their genitals exposed, Ulrich testified, adding that the videos were also all of young boys having sex with one another.

During the hearing, Trusal showed the pictures and videos to Campana, of Williamsport, Chief Assistant District Attorney Ann Targonski, Kear and Ulrich.

Campana was visibly distraught by the images and walked away from the computer several times.

However, he questioned Trusal and Ulrich about the validity and age of the children in the photos.

Trusal and Ulrich said they believe the photos were of real children under 18 years of age. They added that Dr. Pat Bruno agreed. Bruno is medical director of the Children's Advocacy Center at Janet Weis Children's Hospital at Geisinger Medical Center, Danville.

Investigators used Tanner staging, a sexual maturity rating, to determine approximate ages of the children depicted in the images, according to court documents.

Bruno's report was filed as evidence in the case.