Some of the images allegedly show Berndt with his arm around the children or with his hand over their mouths, according to a statement by the Los Angeles County Sheriff's Department.
In addition, authorities say the images depict girls with what appears to be a blue plastic spoon filled with an unknown substance. There were also photos of children with large, live Madagascar-type cockroaches on their faces and mouths.
A search warrant served by detectives on Berndt'shome also led to the discovery of more than 100 similar photographs depicting children, authorities aid. Also found was a DVD depicting adult sexual "bondage" activity. The adults in that DVD are not identified, according to detectives.
As part of the investigation, authorities say they have interviewed more than 80 current and former students, as well as school employees. The victims are identified as 23 boys and girls between the ages of 6 and 10, during a time period from 2008 to 2010.
Investigators are still working to identify 10 of the child victims in the 390 photos uncovered.
Early in the investigation, Special Victims Bureau detectives recovered a blue plastic spoon and an empty container from the trash in the suspect's classroom. The recovered items tested positive for semen, authorities said, and the suspect's DNA matched the DNA profile found on the spoon and container.
Authorities are recommending the children be tested for sexually transmitted diseases, the Associated Press reported.
Berndt was being held Tuesday on a $2.3 million bail.
Investigators are seeking help from the public to identify possible additional victims during the suspect's tenure at Miramonte Elementary School.
Deasy said "crisis counseling and support have been provided for more than a year to the known victims and their families, and we continue to offer those necessary services to new victims as they are identified or any student or parents who requests assistance."