Sounds like Edmunds got marked by mistake. Oh sure, he's got warrants out for other stuff and I'm sure they'd like to pick him up regardless...but it sure doesn't sound like he was the guy lurking behind the milkman on Elizabeth's road that morning...mere hours after he would have nabbed her.
Why would he still be lurking after she was already taken? I think that little tidbit might just be a red herring.