(Image Credit: Hillsborough County Sheriff's Office)

A Florida high school teacher who is accused of masterminding a murder for hire plot against another teacher has a history of disciplinary problems.

In a letter dated November 2001 and obtained by ABC News affiliate WFTS-TV, James Pepe, 55, was chastised for an apparent outburst.

"Your unprofessional conduct… caused a disruption of a school function and created an uncomfortable and hostile situation…" said a letter from the Professional Standards Director at Tampa Bay Technical High School, where Pepe worked at the time.

"Several professionals described your demeanor in terms such as 'hostile,' 'aggressive,' 'extremely volatile,' and your anger as 'alarming,'" the letter stated.

Despite the letter, the station noted that Pepe's evaluations were nearly perfect.

Pepe, a social studies teacher at Bloomingdale High School in Hillsborough County who liked students to call him "Doctor Professor Pepe," was arrested at school on Thursday.

In a Sept. 13 phone call, Pepe, allegedly told an undercover officer that he was willing to pay $2,000 for "an issue that he might need taken care of," according to WFTS-TV.

He is accused of trying to put out a hit on Robert Meredith, a former co-worker. The two men had apparently worked together at Strawberry Crest High School.

Both schools are in the Hillsborough County public school district.

Authorities began investigating Pepe in August after the man he allegedly contacted to kill Meredith became concerned that he was serious and called authorities.

"It had moved beyond just a fixation to an actual anger," a spokesperson for the Plant City Police Department told ABC News.

Police called the FBI which then, according to authorities, taped a series of phone calls between Pepe and an undercover agent.

In the recording made just two weeks ago, in which Pepe allegedly told the undercover officer he would be willing to pay him $2,000, Pepe balked at the officer's request for an in-person meeting.

Meredith told WFTS-TV he knew of Pepe, but did not socialize with him and has no idea why he would be targeted.

"When you are at school you have limited time to talk to co-workers, period. So, as far as going out and having a drink, never," Meredith said. "This came as a complete shock."

Pepe reportedly told police he and Meredith were best friends and had a falling out. He also claimed Meredith was spreading rumors that he was a child molester.

Meredith, who is still a teacher, said he never had any harsh words or a confrontation with Pepe.

"I don't feel that I'm in any way culpable for this," he said. "If there is a problem, it is 100 percent on the other side."

Pepe is being held at Hillsborough County jail on one charge of solicitation to commit murder. He was not offered bail.