WASHINGTON (MarketWatch) -- Internal Revenue Service official Lois Lerner on Wednesday invoked her Fifth Amendment right not to incriminate herself, appearing before a House committee probing the IRS's targeting of conservative groups. Lerner is the first person involved with the IRS scandal to take the Fifth Amendment. She is head of the IRS's division overseeing tax-exempt organizations, and first disclosed the extra review of tea-party groups earlier this month. She told members of the House Oversight Committee, "I have not done anything wrong."