After Redflex Traffic Systems won Chicago’s lucrative red-light camera contract in 2003, its employees gathered to celebrate 2,000 miles away in Los Angeles.

So did John Bills, the assistant commissioner from the Chicago Department of Transportation now accused of helping Redflex cheat its way into contracts that would turn out to be worth $131 million.

The month after Bills allegedly engineered a unanimous vote in Redflex’s favor, former Redflex Vice President Aaron Rosenberg testified that Bills joined the Redflex team for dinner at Asia De Cuba in the Mondrian LA Hotel. But first, Bills told Rosenberg it was time for the Arizona-based company to make good.

“It was time for him to get his,” Rosenberg told a federal jury Tuesday.

And Rosenberg said he delivered, ultimately showering Bills with $14,246 in hotel stays, meals, rental cars, golf outings, computers and even cigars. The longtime city worker, who retired in 2011, is now on trial at the Dirksen Federal Courthouse for fraud, extortion, bribery, conspiracy to commit bribery and filing false tax returns.

Rosenberg is the second of three key prosecution witnesses to take the stand. Former Redflex employee Martin O’Malley testified last week that he passed along $560,000 in cash bribes from Redflex to Bills. Former Redflex CEO Karen Finley is expected to testify Wednesday.

O’Malley and Finley have pleaded guilty to their roles in the bribery scheme. Rosenberg told the jury he received immunity from prosecutors as long as he told the truth. He said he turned over “everything I had” to the FBI — including emails, calendars, and covert recordings he sometimes made illegally.

Prosecutors played one of those recordings Tuesday, in which Rosenberg said he spoke “cryptically” with Bills about money Bills allegedly received from Redflex through O’Malley in June 2008. Rosenberg can be heard on the recording referring to an “envelope from Marty O,” and Bills later refers to it as the “report on all the intersections.”

“Everything’s good?” Rosenberg asks on the recording. “It aligns?”

“Very good, very good,” Bills replies on the tape. The feds later pointed out that O’Malley received a $76,000 check from Redflex that month.

Bills’ attorney Nishay Sanan told jurors last week that it was really Rosenberg who used the Chicago deal to double-dip, seeking reimbursements from his employer after Bills paid him back for the lavish extravagances. Rosenberg denied that Tuesday, testifying Bills never reimbursed him. He also said his superiors expected him to keep it up.

“I had to keep John happy,” Rosenberg said.

Sanan has said the prosecution built its case on “three liars,” including Rosenberg. The former Redflex VP admitted early in Sanan’s cross-examination that he lied under oath as recently as January 2015, when he gave a deposition in a civil lawsuit. Sanan also highlighted Rosenberg’s guilty plea in Ohio to a conspiracy involving Redflex to bribe an elected official there.

The feds call Bills a “greedy public official” who reaped an “almost nonstop flow of benefits” by helping Redflex cheat its way into red-light contracts between 2002 and 2011. Mayor Rahm Emanuel canceled Redflex’s contract in 2013.

Sanan has argued his client didn’t have the clout to pull off the kind of scam alleged by the feds.

“You want a contract, you bribe an elected official,” Sanan told jurors last week.