[FORMER CAPITOL POLICE CHIEF STEVEN SUND]: “These criminals came prepared for war. They came with their own radio systems to coordinate the attack, and climbing gear and other equipment to defeat the Capitol’s security features. I am sickened by what I witnessed that day.” Gripping testimony Tuesday from former security officials and other witnesses to the January 6th siege on the U.S. Capitol, as two Senate committees tried to unravel where the breakdowns in planning and response occurred that allowed the unprecedented violence to unfold. A key point of contention: Whether authorities rejected calling in the National Guard ahead of a rally by Donald Trump supporters out of concerns that doing so might look bad. Former Capitol Police Chief Steven Sund said in written testimony that he had requested National Guard troops two days before the event, but that the then-House of Representatives’ sergeant-at-arms, Paul Irving, told him he was concerned about the "optics" of having the National Guard there. Irving, however, on Tuesday appeared to refute that account:"Let me be clear: ‘Optics’ as portrayed in the media played no role whatsoever in my decisions about security. And any suggestion to the contrary is false.”If “optics” didn’t play a role in the planning stages, it did during a phone call that took place as the attack was happening, testified Robert Contee, the acting police chief in Washington, D.C. “Chief Sund was pleading for the deployment of the National Guard. And in response to that, there was not an immediate, ‘Yes, the National Guard is responding. ’ The response was more, asking about the plan. What was the plan for the National Guard? The response was more, in addition to the plan, the ‘optics’ – how this looks with boots on the ground on the Capitol. And my response to that was simply, I was just stunned.” The FBI also says it warned law enforcement agencies one day ahead of the siege that extremists were planning to commit violence.Sund told the Senate committees he did not see this report himself at the time. Irving also said he did not see the report – but said he was confident a proper plan was in place.PAUL IRVING: “We now know that we had the wrong plan.”Both Sund and Irving have since resigned from their posts. Five died in the Capitol siege. Over 200 police were injured.Senators next week plan to call witnesses from the FBI, the Department of Defense and the Department of Homeland Security.