question any time that we're talking about domestic violence. why does anyone go back? >> the prosecutors hoped any doubt the jury may have regarding his guilt would be wiped away when they called their key witness to the stand. amy was working for smoot during that time. the impression of the nice outgoing man didn't last. >> why did it change? >> he was cold. he got angry easily. not satisfied really r. seemed like he enjoyed getting somebody riled up. >> in court, she testified about what happened the monday following brook's murder. >> on that day, did mr. smooth come into the office. >> he came in that morning when i saw him the first time. he didn't see me and he was crouched down under his desk.