BANGOR — For 20 years, John L. Dudley taught English at Cony High School in Augusta, working his way up to an assistant principal position by 1993.

Now Dudley is suing his former employer for alleged violations of his First Amendment right to free speech and for subsequent harassment, intimidation and demotion after an incident in 1996 that led to his resignation.

A civil trial that got under way before a jury Monday at U.S. District Court, alleges Graham Nye, superintendent of Augusta schools, and Maynard R. “Bob” Young, current superintendent of Bath-area schools and former principal at Cony High School, ignored clear signals that a male science teacher on the Cony High faculty was having sexual relationships with female students.

Through his attorney, Dudley claims he formally reported the teacher’s transgressions — even went to the county district attorney to initiate an investigation — but that his well-intended actions only led to his unexpected termination two years before he planned to retire.

Dudley also is claiming school officials violated the state Whistleblower Protection Act by retaliating against him after he reported the alleged sexual transgressions of a teaching colleague. That claim will be decided by a judge alone after the jury verdict which is expected later this week.

The teacher, Jeff Trundy, was suspected of picking out “one or two girls a year” to whom he paid special, close attention, Dudley testified. The activity had been going on for years, and Dudley testified he had suspected Trundy of sexual relationships with students since the mid-1970s. He decided to take action and gathered “hard evidence” of Trundy’s activity only after he became an administrator and after other faculty approached him with concerns, Dudley testified.

Trundy left the school system in 1996 and moved out of state. He never was criminally charged. He reportedly has not been subpoenaed to testify.

Dudley chose to remain in Augusta to fight a battle he proclaimed “devastating” to him personally.

“After 30 years as an English teacher, 20 of those years at Cony High School, John Dudley made a decision that proved fatal to his career,” said Dudley’s attorney, John Gause, in opening statements.

The Augusta School Department, Young and Nye are represented by attorneys Melissa Hewey and Dierdre Smith of Portland.

In her opening statement, Hewey contended Dudley was relieved of his post as administrative assistant to the principal in April 1996 after showing increasing volatility and for failing to show students respect.

“Respect” is a key word for the Augusta school system, which educates about 3,000 students, 700 of them at Cony High School, Hewey said.

As an administrative assistant to the principal — one of three such people in the building — Dudley was a key disciplinarian in the school.

Yet it was a series of disturbing confrontations with students that led to his being stripped of disciplinary authority, according to Hewey.

In one case Dudley allegedly called a boy a “wise-assed punk” after confronting him in a hallway and writing him up for detention. Dudley testified he called the boy a “punk” but did not use the term “wise-assed.”

In another incident Dudley allegedly wrote on a form that one student was not to “go whining to another administrator” after being written up for detention. The boy’s parents reportedly complained to the superintendent and principal.

In Augusta schools, “it’s not OK to call a kid a name or to bait a kid, and when he rises to it, to punish him,” Hewey said.

Dudley is seeking three years of lost wages as a teacher since his resignation in April 1996. He was paid $39,000 a year for his teaching duties, he testified. He also is seeking three years’ reimbursment for his duties as a part-time administrative assistant to the principal and for his duties as the person who called substitutes to fill in for absent teachers, jobs that paid him about $8,500 a year.

Perhaps more importantly, he is seeking to restore his name and his self-esteem which, he claims, was damaged by his abrupt termination.

“After 34 years in education, I was kicked out. I suffered insults in the community from people on Jeff Trundy’s side. I feared violence. For the last two years I’ve tried to get a job without success,” Dudley testified as his attorney entered into evidence a pile of job applications Dudley had made out.

The trial continues Tuesday.