Capitol Police Officer Harry Dunn recounts emotional January 6 testimony and what took him to a "low place"

It's been a tough week on Capitol Hill where four police officers caught up in the mob violence on January 6 testified in graphic detail about what they experienced.

That includes Capitol Police Officer Harry Dunn, who talked with CBS News' Nikole Killion about the impact of the attack on him and his family and what he wants to see from the congressional investigation. Dunn said he felt every range of emotion - from anger to hope - when he testified Tuesday before the House Select Committee investigating the January 6th attack.