One of three girls who testified in a successful civil lawsuit against the Los Angeles Unified School district that teacher's aide Ricardo Guevara molested them. (Liz O. Baylen / Los Angeles Times / August 18, 2014)

The 13-year-old on the witness stand looked to be an ordinary adolescent, her diffident smile unveiling a set of braces. Her attorney began gently, with questions about her favorite band and trips to the mall.

Then he brought up "Mr. Ricardo" and second grade. The girl buried her face in her hands and sobbed.

When her mother took the stand, she testified that the girl had not been the same since the day the teacher's aide put his hands on her. "I just believe this whole thing changed her life," the mother said. "I don't see her so confident around people. . . . I believe she has no interests."

A jury late last year ordered the Los Angeles Unified School District to pay nearly $1.6 million to the families of three girls molested by Ricardo Guevara, who is now serving 15 years in prison for lewd acts with a child.

But there was something the jury -- and the public -- was never told: This was the third set of accusations that Guevara had molested students. Twice before, when law enforcement officials had decided they lacked the evidence to win a criminal conviction, L.A. Unified officials had quietly put him back in the classroom.

Guevara's case fits a pattern, a Times investigation shows: Repeatedly, the district failed to follow up on sexual misconduct complaints against employees once police or prosecutors dropped criminal actions. Some ended up at new schools. In at least one instance -- involving Guevara -- the new principal had no idea of his history.

In three other cases documented by The Times, the employee went on to be charged with or convicted of molesting another student:

* An elementary school teacher was investigated for allegedly molesting a fourth-grader in 2001. After prosecutors declined to pursue the case, he was transferred to other schools and eventually molested a student in 2004. Convicted of a lewd act, he was sentenced to six years in prison.

* Another elementary school teacher was accused in 2002 of repeatedly forcing a female student to sit on his lap and pose for a camera. Police recommended that the district pursue the issue "administratively." School leaders handled the matter by telling him to stop. The teacher later pleaded no contest to sexual abuse of a child and received 16 years in prison.

* Steve Thomas Rooney, an assistant principal at Markham Middle School in Watts, was arrested last year on suspicion of sexually assaulting a student, sparking public outrage and calls for reform. In 2007, prosecutors had declined to prosecute Rooney for allegedly waving a gun at the stepfather of a student with whom he was suspected of having had a sexual relationship.

Prosecutors say molestation cases are extremely difficult to try because they often depend heavily on the accounts of young, frightened and shame-filled victims. But nothing prevents L.A. Unified from looking further into cases that police or prosecutors decline to pursue. Indeed, district policy has long required school officials to perform an independent inquiry.

Under state law, the district can fire teachers for conduct it deems immoral or unprofessional, even if the acts fall short of criminality. Rooney, for instance, allegedly showed up at the house of the first student at night and drove her around in his car. Had the district substantiated this, it might have been grounds for dismissal.

Teachers point out that students at times fabricate sexual abuse allegations. But instructors are entitled to due process, including administrative and court hearings if necessary.

In the meantime, "if there's some smoke there, then we should err on the side of the security and safety of students," said district Supt. Ramon C. Cortines.

That's the policy. The reality, The Times found, is that the district has erred on the side of protecting its staff.

To protect employees' privacy, files containing past misconduct allegations generally do not follow them to a new campus, according to the district.

Until a year or so ago there was no centralized system for tracking employees accused of child molestation or other serious crimes from school to school. The district relied on index cards that were supposed to be placed in an employee's file to indicate an accusation had been made, according to sworn depositions by district personnel in various civil cases. Even that didn't always happen.

"We didn't do a very good job, historically, on capturing a lot of that," David Holmquist, the district's chief operating officer, said in an interview.

Repeated accusations