INDIAN WELLS, Calif. -

It's been nearly 20 years since the Riverside County Sheriff's Office investigated 59-year-old Robert Keith Bryan for allegedly molesting a child.

The now fourth-grade teacher and "Math Field Day" instructor at Gerald Ford Elementary School came under fire after another sexual assault investigation led to his arrest last week.

Bryan faces 11 charges of lewd acts on a child under 14, and annoying or molesting children.

Free on bail, Bryan's past with the Desert Sands Unified School District is leaving an imprint on the current case.

Records we found from the Larson Justice Center in Indio indicate Bryan was suspected of a lewd and lascivious act in 1992. The incident was dropped by the District Attorney's Office for "lack of evidence."

In March 1994, a parent at Abraham Lincoln Elementary School voiced concern about Bryan touching her daughter, according to investigators.

We've learned that the principal warned him to stop touching and being alone with one or a few of his students at a time -- or else disciplinary action would be taken.

Investigators discovered Bryan was only suspended for 10 days without pay in October 1994 after four students claimed they witnessed him inappropriately rubbing a girl's back on the playground.

A letter written that same month to Bryan on DSUSD letterhead and signed by then Assistant Superintendent Carol McGrew, reads:

"This is the third incident of inappropriate behavior toward girl students in the last three years ... You have been repeatedly told not to touch female students but by your own admission state that this is so much part of your personality that you are unaware that you're even touching your students. This continued inappropriate behavior must cease."

The current DSUSD staff said student safety is a priority and it won't leave any stone unturned.

Assistant Superintendent Sherry Johnstone said, "You're asking me to re-create history. Why was that letter written? I don't know yet. Police are investigating and I'm starting my own investigation."

While the district waits for answers on the current case, Bryan denies the recent allegations of touching more than half of his girl students in ways that made them feel "uncomfortable" or "weird."

"These are horrible accusations, it's a horrible thing if it's true. There is no coming back from this. There is no teaching," said Johnstone.