reporter: police even looked into susanne s shopping habits and found something that intrigued them. susanne bought her groceries at a nearby shoprite, a big supermarket chain. in fact, she was a creature of habit, visiting there 22 times in the month prior to peggy s murder. but on the 23rd time, the night before peggy s murder, susanne shopped at a different store, the one near her mother s house. what did she buy? she bought cleaning supplies, rubber gloves and some other items like that. reporter: had the crime scene been cleaned up? detectives didn t think so. but still found it suspicious. just before your mother was murdered, you go to the shoprite. not the one near your house. the one near your mother s house. mm-hmm. reporter: and you buy rubber gloves and cleaning supplies. i did. i mean, i buy cleaning supplies all the time. i have a cleaning girl. she probably needed rubber gloves. she probably needed floor cleaner. that s interesting.
four days after peggy nadell s murder, family and friends gathered for her funeral. for peggy s daughter susanne, it was all a blur. what s it like to process both the fact that your mom was actually murdered and that you re the suspect? it was horrible. horrible. i lost my mother. i lost my best friend. and now the finger is being pointed at me. as 80-year-old peggy nadell was laid to rest today, her daughter suzanne scaccio has hired a lawyer. people in the area, it s all they talked about. reporter: susanne s friend, darcy greenberg, was hearing it almost every day. there were people who said she did it. oh, she did it. even i heard a neighbor yelled out, when are you going to arrest her for killing her mother?
i m glad everything s okay. we ll disregard for you. have a good night. reporter: it was probably the last time peggy s voice was heard by anyone except her killer. police were convinced still are convinced peggy was letting in someone that she knew. susanne? maybe. but why would she use a tracfone to get her mom to open the door in the middle of the night? she wouldn t have to let me in. i have a key. and i know the how to work the alarm. reporter: right. so if you wanted to kill her, you could have waited until she went to sleep and went in. reporter: unlocked the door and went in. reporter: disarm the alarm. there you go. there you go. reporter: police had warrants for all the family members phones. and a few weeks later they had boxes of records to comb through. detectives analyzed susanne s first. what could you tell about susanne from her cell phone records? a lot. reporter: investigator robyn arias from the westchester county d.a. s office spe
reporter: and on the day of peggy s murder that day was like every other day in susanne s life. there was no change for that particular day. reporter: and you d expect to see a change if somebody was in the process of committing murder for the first time? correct. correct. reporter: suggesting she s innocent? either she s innocent or she has another phone. but there certainly wasn t communication that indicated that something was going to happen. reporter: as hot as detectives were on susanne s trail, they had never stopped looking at the other members of peggy s immediate family. you talked to peggy s son jim and his wife diana right after the murder? yes, when they came up. reporter: they live in florida? correct. reporter: were they in florida at the time of the murder? jim was in florida. and diana said she was in d.c. reporter: why was she in d.c.? she said there was a family wedding. reporter: and the records backed that up. when robyn arias looked
reporter: susanne, who lives in a suburb of new york city, called diana, her sister-in-law in florida. and i said, have you spoken with mommy this morning? she said, you know, i called her at 7:30 and i haven t heard back from her. reporter: now worried, susanne got in her car and drove to peggy s house. as i m driving, i m calling the house, the cell, the house, the cell. no answer. and now i m getting panicky. i pull into her driveway, and i saw the roof of her car through the garage door. and i said, oh, this is not going to be good. reporter: she was right. susanne says she found peggy crumpled at the bottom of the stairs with a knife in her chest. and the first thought was, oh, my god. she tripped on the cat and fell and stuck herself. reporter: then she says she saw the blood. and i said, oh, my god, she must have hit her head when she fell. reporter: and then susanne did something that would later raise a number of questions. i pulled the knife.