CHATTANOOGA (AP) — Emails, recordings and testimony prove that four former employees of the truck stop chain Pilot Flying J conspired to defraud customers in a fuel rebate scam that has already resulted in more than a dozen guilty pleas, a prosecutor said Monday.

Assistant U.S. Attorney Trey Hamilton told jurors in his closing argument that conspirators in the scheme identified potential targets, cheated them out of money and lulled them into a false sense of security.

Benjamin Vernia, an attorney for former sales staffer Heather Jones, said the government had "fallen far short" of proving its case against his client. Attorneys for former Pilot president Mark Hazelwood, former vice president Scott "Scooter" Wombold and former sales staffer Karen Mann will present their closing arguments Tuesday. The trial began three months ago but has taken time off for holidays and bad weather.

Pilot Flying J is controlled by the family of Cleveland Browns owner Jimmy Haslam and Tennessee Gov. Bill Haslam. The Haslams haven't been charged with any wrongdoing. The governor has not been involved in the company in recent years.

Prosecutors say the four defendants participated in a scheme to shortchange trucking customers on diesel rebates. Fourteen former members of the Pilot sales team have pleaded guilty to participating in the scheme, and the company paid a $92 million penalty to the federal government and settled a class-action lawsuit for $85 million.

Hamilton spent much of his closing argument outlining how each of the four defendants was involved.

He said former Pilot account representative Dan Peyton informed Hazelwood that a company had been shortchanged by Pilot. Hamilton also said Hazelwood received emails showing Pilot representatives were offering companies one price and actually charging something different.

Hamilton noted that Wombold worked with Brian Mosher, a former sales director who already has pleaded guilty and who testified in this trial. Hamilton said there's no evidence of Wombold ever telling Mosher defrauding customers was wrong and advising him to stop. Hamilton also cited emails indicating Mann had participated in the fraud as well as testimony that Jones had sent spreadsheets to Mosher to assist in the scheme.

Vernia disputed the notion that Jones willingly participated in any sort of fraud. Vernia said Jones even had asked Mosher at one point if what they were doing was OK, and that Mosher had told her it was.

"Brian Mosher had no compunction about lying to Heather Jones," Vernia said.