The ongoing bribery scandal involving school bus cameras in Dallas, Texas, has claimed another victim. City councilman Dwaine Caraway on Thursday told US District Judge Barbara M.G. Lynn that he was guilty of participating in a photo enforcement conspiracy. The scheme has already taken down former Dallas County Schools superintendent Ricky Dale Sorrells, real estate developer Slater Washburn Swartwood Sr and the entire Dallas County Schools organization, which was shut down by the voters.

"It is time to remove the dark cloud that my actions have brought upon our city," Caraway wrote in a resignation letter on Thursday. "It has been the highest honor for me to serve and lead the citizens of this great city."

It all started in 2009 when Force Multiplier Solutions (that company's IP assets have been acquired by BusPatrol) began looking to sell its automated ticketing technology to Dallas County Schools. The company's leadership decided the most effective means of gaining buy-in from key decisionmakers was to provide campaign donations and outright bribes. Over five years, the agency paid Force Multiplier $70 million, and it became insolvent in the process.

Caraway played a pivotal role in the scam. Force Multiplier CEO Robert Leonard identified the importance of getting a senior member of the Dallas city council to advocate for an ordinance that would allow the installation of automated ticketing machines on school buses. Caraway proved to be an articulate spokesman for the program -- for a price.

Five days after voting to support cameras, Leonard handed Caraway a $5000 check with "loan" written in the memo field. The councilman cashed the check at a liquor store. Caraway made speeches in favor of the program before the city council, and he signed a letter written by Force Multiplier, and sent it to the city of San Antonio in the hopes of drumming up more photo enforcement business.

In total, Caraway took $390,000 in "consulting" payments from ELF Investments, a shell company controlled by Leonard. To help disguise the payments, Leonard and Swartwood created a $270,000 promissory note to allowing the payments to be explained as a loan -- a loan that was never paid back. Leonard also made $40,000 in campaign donations. Other rewards for Caraway included a campaign bus and all-expense-paid trips to New Orleans, Louisiana; Las Vegas, Nevada and Austin, Texas.

"These cases demonstrate our continued resolve to uncover corruption at the highest levels -- the citizens of Dallas deserve honest government," US Attorney Nealy Cox said in a statement.

Caraway's guilty plea covers one count of conspiracy to commit honest services wire fraud and tax evasion. Under his deal with federal prosecutors, he faces no more than seven years in jail, a $250,000 fine (or twice the bribe amount) and three years of probation. He will also pay the IRS $68,906 for failing to pay taxes on the bribes.

Note: This article has been updated.