BAGHDAD, Dec. 30 — Saddam Hussein never bowed his head, until his neck snapped.

His last words were equally defiant.

“Down with the traitors, the Americans, the spies and the Persians.”

The final hour of Iraq’s former ruler began about 5 a.m., when American troops escorted him from Camp Cropper, near the Baghdad airport, to Camp Justice, another American base at the heart of the city.

There, he was handed over to a newly trained unit of the Iraqi National Police, with whom he would later exchange curses. Iraq took full custody of Mr. Hussein at 5:30 a.m.

Two American helicopters flew 14 witnesses from the Green Zone to the execution site — a former headquarters of the Istikhbarat, the deposed government’s much feared military intelligence outfit, now inside the American base.