PIERRE, SD (KELO.com) – South Dakota Legislators are pushing for a subpoena in their investigation of fraud cases at the state Revenue Department. That comes after a refusal to testify by Revenue Secretary Mike Houdyshell. Legislature Executive Board Chair Lee Schoenbeck says attorneys – like Houdyshell – are prevented from speaking in cases that could affect a defendant’s right to a fair trial. But, he says that rule doesn’t apply to other legislators in this case.