Congressional investigators are focusing less on the origins of the Internal Revenue Service's scrutiny of tea party groups and more on how flagging one application led to delays for hundreds of groups applying for tax-exempt status.

In the next phase of inquiries, U.S. lawmakers will seek to figure out why the applications of groups seeking tax-exempt status were stalled throughout 2011, who developed questions the agency later said were inappropriate, and why senior IRS executives did not tell Congress what they knew.

“We still have many questions about why Tea Party applicants faced inappropriate questions, delays and scrutiny,” House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.), said in a statement. “There's a litany of things that happened and a lot of unknowns, including why officials were denying targeting to Congress as it was happening.”