(CNN) — Evidence of a chemical weapons attack in Syria proves “beyond any reasonable doubt” that President Bashar al-Assad’s government was behind it, U.S. Secretary of State John Kerry told the Senate Foreign Relations Committee on Tuesday afternoon. Kerry acknowledged concerns over faulty intelligence on weapons of mass destruction out of Iraq ahead of the U.S. invasion in 2003, but reassured committee members that the U.S. “intelligence community has scrubbed and re-scrubbed the evidence” out of Syria. “We have physical evidence of where the rockets came from and when. Not one rocket landed in regime-controlled territory. Not one. All of them landed in opposition-controlled or contested territory. We have a map — physical evidence — showing every geographical point of impact, and that is concrete,” he said.