The school didn't know because like most other schools, public and private, it conducted only the state-mandated criminal history check, and the teacher had never been charged with a crime or prosecuted. A simple Google search for the teacher's name, however, would have revealed a great deal and raised alarms.

What the school didn't know -- until informed by the Almanac -- was that he also came with a trail of allegations of child molestation involving students he taught at previous schools in three states, starting in the 1970s.

According to the California Commission on Teacher Credentialing, the state maintains a confidential database of complaints against teachers in public schools, but can only publicly disclose "final adverse actions" taken. In this case, those actions would come about only after charges or convictions. As a result, the teacher referred to in this article retains his state teaching credential.

"We of course take these allegations seriously, and we will investigate them immediately," the principal of the school wrote in an email to the Almanac after being informed of the prior allegations. "We will be treating this as a confidential personnel matter and will have no further comment."

"I think the current process identifies people with criminal histories. Obviously if the person has never been arrested, it doesn't help. Also people change over time. There is no way to predict the future," she said. "I think reference checks are only slightly helpful. Because of legal problems, people may give very positive references, but will almost never say anything negative."

Of the schools that do, the searches generally came about as a result of prospective hires listing online profiles, such as Twitter and LinkedIn accounts, on their applications. One human resources administrator at a school that conducts informal Internet searches described the state-mandated process as adequate, but not perfect.

The Almanac surveyed public and private schools in Menlo Park, Palo Alto, Atherton, and Mountain View to find out whether any conducted a more thorough background check than mandated by state law. Administrators were more comfortable discussing their policies off the record. Only three of the 18 schools said they used Internet and social media searches as part of the hiring process.

Through his attorney, the teacher denied any sexual misconduct, including the incidents he admitted years ago to the police. "I have known (him) for more than 50 years and can attest to his honesty, integrity and excellence as an educator," his attorney commented in an email to the Almanac.

The principal of the Menlo Park school that hired the teacher declined to discuss whether its hiring procedures would change, saying only that "we are addressing this internally." The school decided against informing parents of the reason for the teacher's departure. The chairperson of the school board of trustees also refused to comment.

He described a sound policy as one that identifies who will do the search, which sites will be searched with what keywords, who will review the results, how discriminatory or unreliable information will be filtered out, how results get communicated to the decision-maker, and how long results are kept.

Should schools be required to conduct Internet searches as part of their background checks? It's more of a policy decision for the state Legislature, Mr. Gordon said. "It's worth exploring, for sure."

He said that employers running searches on their own should make sure that all applicants are subject to the same searches, and decide how long to keep the search results on file in case a hiring decision gets challenged.

If the search turns up information used to deny someone a job, the applicant is legally entitled to know what the information is and where it came from before that decision becomes final, according to Mr. Gordon.

He listed several concerns. Employers, including schools, might find information that they legally can't consider when hiring, such as an applicant's religious affiliation. To safeguard against that, an employer may contract a third party to conduct the checks, but then they also need to be sure the check complies with the Fair Credit Reporting Act. The law's provisions include getting the permission of the job applicant and ensuring that the information is accurate -- a challenge in the "anything goes" online environment.

Internet searches create their own set of legal issues, however. "It seems easy, like why don't we just Google everyone?" said Philip Gordon, an attorney with the San Francisco-based law firm Littler Mendelson who specializes in privacy protection and gives nationwide presentations on social media issues for employers. He referred to a survey by social media monitoring service Reppler last year that found 69 percent of 300 business recruiters had rejected a candidate based on social media profiles.

Those may be hard questions, Sen. Simitian noted, but they must be asked "when talking about employees whose misconduct is so egregious that they can really do serious harm to the next student."

Drawing on his experience as a school board member and practitioner of school law, Sen. Simitian said that too often, schools decide to get rid of an employee quickly with a quiet dismissal. "I would encourage every school or school district to ask themselves, can we in good conscience simply brush this under the carpet? Or do we have an obligation to confront the problem in a way that helps ensure that this is not a problem simply passed along to the next school?"

"But why on earth wouldn't you take 60 seconds to Google a name and see what pops up? See if it raises questions that should be asked and answered."

"Online is a pretty easy and immediate, albeit imperfect, screen," he said. "The challenge with the online world is that it's unregulated and unreliable. Anyone can say anything and I think you have to be very mindful of that.

How thorough should a background check be? State Senator Joe Simitian, D-Palo Alto, said he's surprised by how many employers in any kind of business, not just schools, don't do a minimal check by picking up a phone or querying Google.

One alleged victim said: "That's something you've got to get -- he has done amazing things with kids that were life changing. For those people that he's helped so much there's no capacity or context for them to see him in that other life. And that's OK."

When the teacher resigned from a position in 2002 in the wake of allegations of inappropriate conduct with a student at a school in another state, hundreds of parents and students came to the teacher's defense.

The Almanac interviewed 10 former students and colleagues who knew the teacher decades ago. One alleged victim, now a grown man with children of his own, went to police in 1996 upon learning that his former teacher wanted to adopt a boy. He said he met the man as a 12-year-old after transferring to a new school in another state. The two eventually became so close that they even lived together for several years in the wake of a rocky family relationship.

With no charges and no arrests, the teacher's background turns up only in newspaper articles archived by Google and in online forums -- not the state-mandated Livescan and DMV background checks that schools use to screen job applicants.

"This was stuff that was not some accidental touching or rubbing of body parts. This was purposeful and intentional and amounted to molestation," the deputy police chief, who had participated in the investigation as an officer, told the Almanac.

During the 1990s, police in another city ran into a dead end due to the statute of limitations -- several alleged victims were adults before they came forward to report their encounters with the teacher as teens -- and because the foster parents of one child did not want the boy to testify. The investigation stalled despite the man admitting to having sexual contact with two boys, according to a police report obtained by the Almanac.

The Almanac is not disclosing his name because the incidents are alleged to have happened so long ago, the teacher has never been arrested or charged or sued, and he denied the allegations through his attorney. He has retired from teaching now and left California, the attorney said. The Almanac is also not disclosing such details as the names of alleged victims or specific dates that could unmask his identity.

She discovered several of his former students who revealed that the teacher had molested them and who were willing to share their stories publicly. Three had previously filed police reports that led to investigations in California, including one within the last year about incidents that occurred during the 1970s. No charges have ever been brought because time allotted by the statute of limitations had passed. None of the victims has filed civil lawsuits against the teacher.

When she tracked him down and found that he was still teaching, she became concerned and began reconnecting with other former colleagues and students to help her decide what to do.

The Almanac was tipped off by a former friend and colleague of the teacher living out-of-state who had sought to reconnect with the teacher after losing contact years earlier. Much to the friend's surprise, when she began searching the Internet for his name she came across several newspaper reports about molestation allegations.

When background checks miss the mark