it was her daughter-in-law diana. detectives knew that diana's friend, karen hamm-samuel, had bought the tracfone that called peggy's house just before she was murdered. diana had told police from the beginning that she'd been in washington, d.c., to attend a wedding. but her alibi was wobbly. diana couldn't account for her time in d.c. >> she hit washington at about 9:30 and didn't reappear again until about 8:00 the next morning. >> reporter: so detectives called diana, asking her to fill in the gaps. >> i just have to confirm that you were up in washington. is there somebody i can talk to? >> what do you mean? >> we had to keep it real simple with her. listen. we just want to get you cleared. where did you spend the night? >> reporter: what did they not tell diana? detectives had a warrant and they were tapping her phone. police now sat back and listened as diana made multiple calls to