Signaling that it intends to conduct an aggressive investigation into how the Internal Revenue Service targeted certain conservative-leaning groups, the Senate Finance Committee has asked the agency's outgoing acting commissioner to document any communications with top Obama administration officials about the unfolding scandal.

Sens. Max Baucus (D-Mont.) and Orrin G. Hatch (R-Utah), who lead the Finance Committee, wrote to Steven T. Miller on Monday making 41 specific requests for information. They include documentation of all attempts to elicit information from groups seeking tax-exempt status; a list of all the words and phrases used to target applicants for additional scrutiny; how IRS officials discovered that employees were inappropriately targeting certain groups; and all internal communications between employees working to review the groups.