Well I think it's interesting that LE announced they are "taking the weekend off". I can't remember the last time I heard that. It's usually we are working around the clock, won't stop until we find the killer, tirelessly, endlessly pursuing, until we find, etc.
I think they made that announcement to make the killer uneasy in a reverse psychology type of way. I also think they also have a pretty good idea who it is and are just building their case now to make a rock solid arrest.
By saying they are taking the weekend of may give the killer a false sense of relief and he/she may slip up when they are feeling a bit of temporary relaxation. Or, it might make them think that they, LE are not letting on to something and really are not taking time off.
Maybe someone is talking, and giving this lull before the storm, might bring the killer in. All of this is just speculation on my part. I just found announcing that they were taking time off odd. Even if they are, why announce it? Interesting strategy.