Good point. I wonder if the tipline people are giving their full name when they answer. That would be unwise. One thing the police should expect - and even hope for - when setting up a tipline is that the killer will call.
From remarks made on the Today show, it also sounds like the tipline setup is a fiasco - e.g. scribbling notes on carbon paper and handcarrying to other jurisdictions. There's a lot more they could do with what's available now. There should be a digital archive of all calls.