Wisconsin Constitution
Article IV - Legislative
Section 15 - Exemption from arrest and civil process.

Members of the legislature shall in all cases, except treason, felony and breach of the peace, be privileged from arrest; nor shall they be subject to any civil process, during the session of the legislature, nor for fifteen days next before the commencement and after the termination of each session.

The privilege under this section can be invoked by a legislator only if the legislator is subpoenaed, not if an aide is subpoenaed. State v. Beno, 116 Wis. 2d 122, 341 N.W.2d 668 (1984).

The members of the Wisconsin Constitutional Convention did not intend to create a legislative privilege from criminal arrest and prosecution when they included article IV, section 15 in the Wisconsin Constitution. The phrase “treason, felony and breach of the peace" in that section was intended to mean all crimes. State v. Burke, 2002 WI App 291, 258 Wis. 2d 832, 653 N.W.2d 922, 02-2161.