"Mens rea" means basically "guilty mind," and here is the evidence of Lois Lerner's mens rea:
Perhaps a quote from Lois Lerner might explain the necessity. Blogger Patrick Frey found this potent advice from the woman at the center of the targeting scandal from a November 2011 interview with Bloomberg Business Week http://www.businessweek.com/magazine/the-irs-takes-a-closer-look-at-colleges-11172011.html that could explain quite a bit about the IRS’ motivations.
Lerner, interviewed at the time in regard to an investigation into not-for-profit colleges and universities, underscored the importance of aggressive interrogatories to discourage organizations from pursuing tax-exempt status. Business Week reported Lerner’s response: “Receiving a thick questionnaire from the IRS, she says, is a ‘behavior changer.’”