I saw this article and they are mostly obvious but as you read through them it really makes your mind race thinking about the events that evening.
http://www.cbs8.com/Global/story.asp?S=12112885
Possible senario:
Visitor or member to inner circle of the players involved becomes aware of the infamous bicycle "fight". LB is very familiar with the perp or is aware of their presence in the houses she visited throughout the day so she doesn't feel threatened, I mean, why should she. Perp comes across LB on Maple and inquires "where is your bike", then offers LB to go with him and pick up the bike which he will get fixed for her, so she can ride by her house and rub it in her brother's face. Despite the fact that it is almost 10 pm at night and repair shops are not open, a young child would only be thinking about their bike getting fixed. Which never happened.
Any locals recall someone being extraordinarily interested in the broken bicycle or the fight between LB and her brother?