jennifer graves woke up to a fresh blanket of white spreading down the slopes and out across the frigid valley floor. she just finished taking a shower when the phone rang. it was a lady from a local chi care facility in west valley city. jennifer's little nephews hadn't shown up. did she happen to know where they were? >> it had been a couple of hours and they were expected. they had never cancelled or anything. >> strange, and completely unlike the boy's mother, jennifer's sister-in-law, susan powell. >> so we were immediately concerned. we left right away to go over to the house. >> the day care woman, debbie was her name, said she had already been there, seemed like nobody was home. >> debbie said that she had knocked on the door and tried to rouse them and everything. seeing no tracks in the snow outside in the garage. >> had they overslept or gone away someplace without thinking to call day care? or was it something awful? that's where jennifer's mind went, her husband's too. >> we were pretty much beside ourselves with panic, thinking they must be in there dead. they must be in t

jennifer's grave itself seemed to be throwing up strange tantalizing clues. >> almost as if she was downng it to us. >> nine years after jennifer's death, her father, jim, was tending her grave clearing away weeds. >> he was edging around the back of the headstone, and he was down here with just a little edger to clear the grass away, and he popped out a fraternity ring. >> had to be a fraternity with those distinctive markings. >> odd that after that long a period of time that someone would come and obviously felt this tremendous remorse or whatever their feelings were that would have to come back to the grave site and put this under their headstone. so we took pictures of it, and we sent it to florence county. >> but not before they searched the internet to identify the fraternity that issued such a distinctive ring, and soon they had their answer "tau kappa epsilon," a new and small fraternity then at francis marion. and one of its founders on campus, number 26 here on the roster of members was chris woodson. an enticing clue that only contributes to a case of severe frustration. >> i

. >> but josh's own sister, jennifer graves, has her doubts. >> his actions have told me all along there's>> after all, josh powell is the last person to have seen her alive. he says he left to go camping with their two very young boys around midnight with a serious winter storm on the way. susan's parents among others have questioned the story. >> she would not leave the children. for her to leave the house without her purse or her cell phone or anything is just -- she would not do that. >> susan and josh seemed to have a fine marriage, as far as anybody could tell, at least. >> they're kind of sfil in the newly wed stage even though they were married for three years. they were kujdzing and hugging each other. >> josh's father interpreted susan's affectionate in a different way. >> susan was very open, and i would say very aggressive in male/female relationships. she called the shots. >> behind steven powell's public theories about susan and sexuality was evidence of private activities that have landed him in jail. he's now awaiting trial on charges of voyeurism and possessing child porno

. >> reporter: but josh's owner sister, jennifer graves, has her doubts. >> i do still believe that myther must be responsible in some manner. his actions have told me all along that there's something wrong there. >> reporter: after all, josh powell is the last person to have seen her alive. he says he left to go camping with their two very young boys around midnight. with a serious winter storm on the way. susan's parents, among others, have questioned the story. >> smeld not leave the children. and for her to leave the house without her purse or her cell phone or anything, it's just -- she would not do that. >> reporter: so what did happen? >> it's a puzzle. until you can fit the pieces of that puzzle into what the picture is, we cannot make improper assumptions. >> susan and josh seemed to have a fine marriage as far as anybody could tell, at least. >> they were kind of still in the newlywed stage even though they had been married for three years already. they were always cuddling and hugging each other. >> reporter: so josh's husband, steven powell, interpreted susan's nature in a

jennifer johnson, nbc news, washington. >>> thousands of grave markers at the country's most prominentary cemetery may have been misplaced or misidentified. the army released a year-long report that shows there could be discrepancies between headstones and paperwork with an estimated 64,000 markers at arlington national cemetery, 1 in every 4 grave stones. the cemetery says problems like civil war era logs, illegible paperwork, and changes in burial procedures could be to blame. the army and outside analysts plan to review every questionable case. those reviews are expected to be completed by next summer. >>> a serial arsonist in the east bay has been arrested after a complex six-month investigation. i want to show you surveillance video that helped investigators tie 53-year-old thomas hartman, they say, to several dumpster fires in the east bay. they say you can see the pittsburg man standing near a dumpster on the right-hand part of your screen. he then get in this his car, drives away, then moments later, the dumpster catches fire. hartman is accused of setting more than 45 fires in