Mass. corruption case built around e-mail trail

Federal prosecutors have relied on a trail of e-mails to build their corruption case against former Massachusetts Speaker Salvatore DiMasi and three associates.

A federal indictment released Tuesday says that in one e-mail, DiMasi friend and accountant Richard Vitale warns another member of the alleged conspiracy not to refer to DiMasi by name or title.

In later e-mails, Vitale refers to DiMasi as "Coach."

After DiMasi, Vitale and DiMasi's friend Richard McDonough allegedly helped a software company secure a lucrative state contract, a company executive sent an e-mail to a fourth member of the alleged scheme, Joseph Lally, asking him "to thank Dick and Sal for getting this contract closed."

The four maintain their innocence and are free on bail.