GALENA PARK, Texas -- Detectives returned to North Shore High School Thursday to continue their investigation of a teacher accused of exposing himself in his classroom while looking at child pornography, KPRC Local 2 reported.

Fernando Gonzalez, 34, was an algebra teacher at the ninth- and 10th- grade campus.

Harris County Precinct 3 deputy constables said the incident happened during Gonzalez's conference period shortly before classes were dismissed on Wednesday.

Four to 6 students saw him through the door's window, officials said.

"Students were walking past his classroom and looking through the window when they happened to see a teacher involved in a questionable activity," said Bourke Meagher, the assistant superintendent.

"It's kind of scary that you send your kids to learn and you have teachers doing that where students can see," parent Kelly Scoby said. "I don't understand how you can have that going on."

Gonzalez was charged with two counts of possession of child pornography. He made his first court appearance at about 4:30 a.m. Thursday. He was jailed on a $20,000 bond.

"It's not right to be doing that, especially with teenagers around," parent Janie Gonzalez said.

Court papers state Gonzalez tried to flee when the principal confronted him. Investigators said that he later confessed to having a large quantity of child pornography on disks and on a computer in his classroom. Officials said they found pornographic images of children as young as 5 years old on one of the disks.

Detectives seized two computers from the school, as well as two computers from Gonzalez's home.

Child pornography has only been found on one of the school's computers, investigators said.

"He's embarrassed and ashamed, as very well he should be," Capt. Ken Jones said.

School officials said Gonzalez had been with the Galena Park Independent School District for the past 10 years. Officials said Gonzalez passed his initial background check, as well as yearly ones given out to all school district employees.

"Whether you are with us 20 days or 20 years, each year we renew criminal records check and on all of those, on this particular employee, there's no indication of criminal history," Bourke said.

Gonzalez has been terminated from the district.

If convicted, he faces up to 20 years in prison.

A letter was sent home with students to inform parents about the incident.