My question involves a traffic ticket from the state of: California

Hi, I made a right turn on red on the road which has a traffic photo device. I saw the road was safety for me to make a turn about 10:00 p.m.. Unfortunately, there was a sign that read " No turn on red when children are present" and there were no children at that time. I saw a flash light went on and now I'm worry for that.
What is really mean behind the "No turn on red when children are present"
Please help.

Thanks