For the second straight day and the third time in one week, IRS officials will testify Wednesday in front of Congress about the agency's improper targeting of conservative groups.

Highlighting today's House Oversight Committee hearing is IRS official Lois Lerner's decision to invoke the Fifth Amendment and not answer questions. Lerner is still under subpoena to testify, meaning she will have to invoke her rights in person -- and likely repeatedly.

Also appearing is Douglas Shulman, the former IRS commissioner who also testified in front of a Senate committee on Tuesday. Rounding out the witnesses are the inspector general who investigated the wrongdoing -- J. Russell George -- and Deputy Treasury Secretary Neal S. Wolin, who learned of the investigation into the IRS's targeting last summer.

Stay tuned below for live updates on the key moments.