IRS' last two commissioners deny lying; official to take the 5th WASHINGTON - As the Internal Revenue Service's last two directors struggled to provide answers Tuesday about the agency's improper scrutiny of conservative groups, a lawyer for another key IRS official said she would invoke the 5th Amendment rather than answer questions about the screening and why she didn't tell Congress about it. Lois Lerner, director of exempt organizations for the IRS, will assert her right against self-incrimination during her scheduled appearance Wednesday before the House oversight panel. The news about Lerner is yet another low point for the IRS and the Obama administration in their struggles to explain how IRS employees in a field office in Cincinnati targeted some groups that had applied for tax-exempt status. Lerner's criminal defense attorney, William W. Taylor III, sent the committee a letter saying that he advised Lerner, because of a federal criminal investigation, not to answer questions about the screening or about what the committee said were "false or misleading" responses she made four times to the committee's earlier queries about the IRS' actions. "She has not committed any crime or made any misrepresentation, but under the circumstances she has no choice but to take this course," Taylor wrote to Rep. Darrell Issa (R-Vista), chairman of the House Committee on Oversight and Government Reform. He asked that Lerner be excused from appearing, but an Issa spokesman said she would be expected to show up anyway. "Chairman Issa remains hopeful that she will ultimately decide to testify tomorrow about her knowledge of outrageous IRS targeting of Americans for their political beliefs," spokesman Ali Ahmad said. That news came as the last two commissioners of the agency, Douglas Shulman and Steven Miller, endured a barrage of hostile questions from members of the Senate Finance Committee about who was responsible and why they didn't reveal the problems earlier. And a White House spokesman defended the decision by senior officials not to brief President Obama about the matter. White House spokesman Jay Carney said there was "nothing the president could or should do until that process was completed." New details have emerged this week showing that, with an audit by an inspector general nearing release, officials at the IRS, the Treasury Department and the White House started talking a month ago about some kind of preemptive public disclosure about the improper targeting. In late April, IRS officials reported to the Treasury Department that they were thinking about having Lerner talk about it in a speech, with an apology, according to a Treasury Department official. Treasury officials "expressed some concern" about the idea but "deferred" to the IRS. About the same time, the IRS floated the idea of having Miller reveal the targeting during congressional testimony. Once again, the Treasury Department said it was the IRS' call, according to a statement from a Treasury official. And the Treasury Department also knew in advance that Lerner would reveal the targeting on May 10, answering a planted question during an American Bar Assn. conference. The disclosure quickly turned messy, with Lerner struggling to answer questions during a follow-up call with reporters. The White House knew about the speech idea but not the plan to plant a question, the Treasury official said. Miller, the acting IRS commissioner forced to resign last week, said he took responsibility for that bungled rollout strategy. "Did not work out," he said bluntly. Obviously the entire thing was an incredibly bad idea. Lerner, head of the unit that scrutinizes nonprofits for the IRS, came to the agency from the Federal Election Commission in 2001. In June 2011, according to the inspector general's report, Lerner learned that employees in Cincinnati were using terms like "tea party" and "patriots" to cull applications from nonprofit groups for review. Lerner immediately ordered changes, the report says. But in January 2012, someone at the IRS put out another email telling screeners to watch out for groups that used other political terms, including those involved in educating on the Constitution. The groups raised protests after the IRS sent them letters with a long list of questions, including the identity of their donors and the names of the people invited to their events. Congress started asking questions. But Lerner, along with other senior IRS employees, did not reveal the improper targeting before May 10. During the hearing Tuesday, senators on the Finance Committee accused Shulman and Miller of deliberately hiding the matter from Congress. It's a lie by omission. There's no question about that in my mind," said Sen. Orrin G. Hatch of Utah, the committee's top Republican. "I did not lie, sir," Miller responded. Shulman also said he wasn't trying to hide anything.