Updated

An elementary school principal has been charged with molesting a 13-year-old student, and police said they're investigating the possibility that there could be other victims.

Michael Alcoser, 41, was arrested Tuesday on a charge of aggravated sexual assault and jailed on $75,000 bond.

Police searched Alcoser's home last week and took computers, digital cameras and videos as part of an investigation that was prompted by a mother's complaint, according to an arrest affidavit. The mother claimed a school employee told her of rumors that Alcoser had "done something" to her son.

The affidavit said police confiscated images of the alleged victim, two compact discs that "depicted adult men having sex with adolescent male children" and handwritten notes from children that were "inappropriate and sexual in nature."

Police also seized pictures of other unidentified children.

"In these cases, historically, we are never done with one victim," Police Sgt. Gabe Trevino said. "Odds are good there may be more victims."

Family members of Alcoser could not be reached for comment Tuesday.

The South San Antonio Independent School District said Alcoser was placed on administrative leave from his position at Carrillo Elementary School pending the outcome of the criminal investigation.

"We're shocked by the allegations," district spokesman Ed Suarez said. "We're cooperating in every way, and have been cooperating, with the police. Now we just have to let the legal system take its course."

Alcoser has worked in the district as a teacher, vice principal and principal. He spent 16 years at Price Elementary, the same school he attended as a child, as a teacher and administrator. He was transferred to Carrillo Elementary in 2005, the district said.

Background checks conducted at the time of Alcoser's hiring and two years ago did not reveal any problems, officials said.

According to the arrest affidavit, the boy said the assaults began when he was 11 years old and in the fourth grade. Between 2004 and 2006, the boy was fondled and photographed in his underwear, sometimes in Alcoser's school office.

The boy has also accused Alcoser of performing sex acts on him in Alcoser's school office and of taking inappropriate pictures at Alcoser's home, the affidavit said.

Police arrested Alcoser on Tuesday at an undisclosed medical facility. A family member told police she believed Alcoser was a danger to himself, the affidavit said.

School officials said counselors would be sent to Carrillo Elementary.