The community at Granada High School in Livermore is having a tough time thinking of Johnson as an accused sex offender when just yesterday she was known as "Ms. J," the math teacher.
"I'm really, really shocked because she was a very nice lady and she really showed that she cared for the kids and to this moment I think it's not true," parent Monica Gottero said. "I hope it's not true."
Johnson faces 24 charges of sexual assault. The wife and mother is accused of having sex with the teen boy from December to May of last year.
The principal of the school called police when a student came forward and told an adult about the possible crime.
"The staff is reeling, the students, the whole community is, and our goal is to get us all through it together," Granada High School Principal Philomena Rambo said.
Police say Johnson had the boy in class and then corresponded with him through Facebook, text messages and through the game "Words With Friends," a Scrabble-type game played online. School officials say they are trying to navigate their way through this new frontier of social media and teacher-student relationships.
"We certainly want there to be connections between students and teachers, we think that's important, but we also know that there's appropriate ways to do that," said Assistant Superintendent Chris Van Schaack.
The school just recently changed its policy, but officials say they don't have much control of what happens beyond the school grounds.
"There have been recent court cases that limit us in what we can demand," Van Schaack said. "Teachers do have certain freedoms and they can communicate with students legally outside of school."
Police are encouraging parents to talk to their kids about their social media relationships. The school's old policy only mentioned computers. The new policy includes smartphones and tablets and states that communication must be age appropriate, respectful and not harassing.