It was unclear if Garcia-Bratcher had ever reported the bullying to the school.
"She is a good mom who protected her daughter," Adams said. "She did nothing wrong. She's a good mom. It's that simple."
The comments came after prosecutors asked for more time to decide whether to bring criminal charges against Garcia-Bratcher.
Deputy District Attorney Anne Masterson said more investigation was needed. Judge Dana Simonds agreed to let both sides return June 19.
Garcia-Bratcher, who was free on $30,000 bail, was arrested Saturday following an initial police investigation.
A sheriff's spokesman said Garcia-Bratcher was on campus Friday to register one of her children when she saw her son and asked him to point out the boy who was bullying her 10-year-old daughter.
She allegedly walked up to the boy, grabbed his neck and then shoved him, a sheriff's spokesman said.
The boy ran to a teacher with red marks on his neck. Photographs were taken and police were called.
This week, sheriff's Lt. Steve Brown said investigators could find no evidence of contact between the boy and Garcia-Bratcher's daughter. He suggested Garcia-Bratcher may have gotten the wrong boy.
But Adams said it's clear the 12-year-old was the bully who was tormenting his client's daughter. He said Garcia-Bratcher never laid a hand on him.
"She did not get the wrong boy," he said. "The boy is lying if he says otherwise."
He said the lack of charges suggests prosecutors have little evidence against the mother. His own investigation turned up evidence pointing to Garcia-Bratcher's innocence, he said.
He did not say what that evidence is.
The Santa Rosa lawyer said Garcia-Bratcher was supported by parents everywhere who are tired of having their kids victimized by school bullies. The case, which attracted TV crews from around the Bay Area, has garnered national attention and is the subject of bloggers and columnists.
"My client is a folk hero all over the world," he said.
Adams said there is a history of bullying at the school and officials have done nothing about it. And he accused District Attorney Jill Ravitch of stalling a decision on the case until after her June 3 re-election to avoid losing votes.
"She's going to annoy many people by charging my client," Adams said.
Ravitch released a written statement Thursday confirming no decision had been made. She said authorities were continuing to look into the matter and asked for anyone with information relevant to the case to contact the Sheriff's Office.
"After ensuring a thorough investigation has been completed, our office will review all the evidence and issue a decision," the statement said.
Superintendent Jennie Snyder said the school district also was conducting an investigation and would take any corrective actions deemed necessary. She said the district takes bullying complaints seriously.
"We really want to get to the bottom of what happened," Snyder said.
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