detective kathleen decker took the stand. >> when you first saw david at his residence, i believe youry anxious and upset. >> yes. >> the defense willingly conceded that david pietz was a crummy husband. but skirt-chasing didn't give him a motive for murder. >> dave pietz isn't the first guy to step out on his spouse. all of you, certainly, know of people that have done that. have they killed their wives or husbands or anything like that? >> and, the defense countered, that if anyone had secrets to hide, it wasn't dave. it was nici. >> there's another side to all this. >> the defense now turned the focus to nicole pietz, and the last few weeks of her life. >> raise your right hand. >> the lawyers called to the stand their main witness, nici's doctor, carol waymac, nici's primary physician for five years. >> you knew nici's history, that she had trouble has a young woman. >> i did. >> and had actually been in rehab at one point. >> and we had talked about it throughout her care with me. >> so when nici came into the office complaining of severe back pain at the end of 2005, doctor waym