study, at age 7, 15% of girls had breast development and 10% of girls were developing hair already, pubic hairby age 8, which used to be the lower limit of normal, it was a much higher rate with 27% of the girls having breast development and about 19% having hair. >> so i know that that is alarming to a lot of families who aren't used to this. it kind of changes our brains. we have to think about this differently. so in your study, i know it's a long-term study, it's been going on for years. what are you learning so far. what are some of the triggers do you think? >> we are looking at a lot of different things. so the things that we're examining are environmental or chemical determinants that may promote early puberty. so for example, we are looking at nutrition, including breastfeeding. our girls at kaiser were girls that were born within keiser. we're able to lock at what kind of feeding their mothers were able to do. and then moving on to asking questions about what they eat on a regular basis now. so we're looking at nutrition. we're looking at location of homes. is your home next to a fre

. >> these were sent to the lab and found to be pubic hairs of an african-american. >> but this didn'te description given by the eyewitness who said a caucasian followed laura into her apartment. >> if you know anything about hairs, hairs fall off of people all over their body every day. she also had a friend who was an african-american and had been in her apartment and readied her apartment when she moved in. >> police interviewed laura's african-american friend. and he had an airtight alibi. he was with friends on the night of the murder. with no solid leads, police turned their attention to the bar laura visited before she returned home. when investigators questioned patrons of the bar, they found laura got into an argument with sam freeman, a 26-year-old veteran of the u.s. army. >> laura accused him of hustling these two young men playing pool. whatever happened wasn't something that came to blows, but there was a disagreement over a pool game, and laura had confronted him. >> candace shipman was working the bar that night. she said the altercation was minor. >> just got a little

. >> dumb luck kept that towel from burning up and burn being the pubic hair with it. >> investigators now had dna evidence from both crime scenes. biological from the rape test kit and the hair from barbara walsh's apartment. scientists compared robert parker's dna to those dna samples. >> robert parker's dna profile was compared to the profile previously generated from the vaginal swabs. it was a match. >> robert parker had denied ever be being in the victims' apartments. and now the evidence directly contradicted him. two years after the crimes, 23 year old robert parker was arrested and charged with two counts of murder. prosecutors believe parker spent weeks watching his victims. with renee powell, he waited in the woods next to her apartment. when she went to the laundry room in the base. she left her door open. he went inside, grabbed a knife from the kitchen and hid. when rent hay returned, he attacked binds her arms with lamp cords from inside the apartment, then sexually assaulting and stabbing her to death. he grabbed some items of value, a vcr, a coat, dismantled the smoke

. >> one was a body hair, one was a pubic hair that was recovered from susan's body. >> phillips willingly provided hair samples for comparison. based on microscopic examination, phillips' hair was not similar, so he was eliminated as a suspect. despite the hair analysis, susan's family was convinced that john paul phillips was susan's killer. >> and they didn't take phillips into custody at the time. they didn't arrest him or charge him, which i didn't understand at the time, because i thought that they had enough reason to. >> later, phillips committed several assaults that landed him in jail. >> he went out to the devil's kitchen, spotted a young lady and her boyfriend at one of the campgrounds, approached them with a gun. he went over to carterville and kidnapped a girl, too. >> but police finally got a break in susan schumake's case. first, they found susan's yellow backpack in the piles fork creek behind the dormitories. her wallet was missing. friends said she usually carried about $10. and a campus worker found a small red bag with some toiletry items not far from where susan schum