I had an idea that I wanted to share.
(Assuming the police do not have damning forensic evidence to prove MB is guilty)
What if April and her friend were playing, and then the other girl went inside to use the bathroom or something, and April was no where to be seen upon returning outside to play. Perhaps the woman instructed her daughter to say that she saw April get into a van. Why would she do this? I can imagine that she might not have relished the idea of telling her friend that her daughter disappeared and she had not been keeping an eye on her the entire time.
Given the fact that the details of the van do not match the description of MB's car, I would not think that she was trying to frame him or get revenge. I think that she may not have expected the authorities to suspect MB and thought the left drive vehicle description would lead the police to suspect the perp was not from the area. Otherwise, I can't understand why the witness did not give a description of the kidnapper or simply identify him as "so and so's father".
Question for locals: Are left handed drive vehicles mostly owned or driven by people outside the area, e.g., foreigners, visitors, etc.?