It was the dress that she was wearing (and maybe the last outfit she wore) the night before she went missing and came home from the neighborhood party next door. BC washed the dress and told others, including her friends to look for a black dress she was wearing to give it to CPD, it turns out that her dress was this one a Teal one. BC also said the reason he washed the dress was because when she got home there was a stain on it and so he washed it for her. Her friends testified earlier in the trial that there was never a spill or stain on that dress.
Hope that helps.
So he washed the dress - Wasn't it found over the laundry hamper ( i assume to be washed) I guess I need to read and catch up with the facts of the case.