A third Louisiana resident, and second from Ruston, has been charged with insider trading in connection with The Shaw Group’s 2012 acquisition by Chicago Bridge & Iron Co., federal prosecutors said Thursday.

Billy J. Adcox Jr., 44, made more than $37,000 from his alleged illegal insider trading activities, according to a federal grand jury indictment returned Wednesday against the Ruston man.

The indictment alleges that Scott David Zeringue, while serving as vice president of construction operations for Shaw in Baton Rouge, obtained inside information in 2012 about the impending merger between Shaw and CB&I and passed the information along to his brother-in-law, Ruston dentist Jesse H. Roberts III, who in turn shared the information with Adcox.

Adcox then passed the information to someone identified in the indictment only as John Doe.

Zeringue, 48, who no longer works for Shaw, pleaded guilty in June to one count of conspiracy to commit securities fraud.

Roberts, 43, was indicted last month on federal conspiracy and securities fraud charges.

Also last month, the U.S. Securities and Exchange Commission accused Zeringue and Roberts of insider trading. The SEC said the alleged frauds totaled nearly $1 million.

Federal law bars officers, directors and other members of publicly traded companies from using secret company information to profit from stock trades.

Adcox’s indictment was announced by U.S. Attorneys Walt Green and Stephanie Finley. He is charged with securities fraud and conspiracy to commit securities fraud.