The Internal Revenue Service's scrutiny of conservative groups went beyond those with "tea party" or "patriot" in their names—as the agency admitted Friday—to also include ones worried about government spending, debt or taxes, and even ones that lobbied to "make America a better place to live," according to new details of a government probe.

The investigation also revealed that a high-ranking IRS official knew as early as mid-2011 that conservative groups were being inappropriately targeted—nearly...